6-aryl pyrimidine compounds and method for treating viral infections and inducing interferon production

ABSTRACT

6-Aryl pyrimidinol compounds, also can be named 6-aryl pyrimidinone or 6-aryl-isocytosine novel compounds, also novel and old compounds useful for treating viral infections and inducing interferon production. Dosage forms and method of treatment are disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Ser. No. 464,791, filed 7 Feb. 1983, abandoned; which is a continuation of U.S. Ser. No. 06/330,360, filed 14 Dec. 1981, abandoned; which is a continuation-in-part of U.S. Ser. No. 06/117,314, filed 31 Jan. 1980, abandoned; which is a continuation of U.S. Ser. No. 06/022,205, filed 19 Mar. 1979, abandoned.

BACKGROUND OF THE INVENTION

The preparation and use of 2-amino-5-halo-6-alkyl-4-pyrimidinols as antiviral agents is known (U.S. Pat. No. 3,956,302 and Nicols, Weed and Underwood, Antimicrobial Agents, Chemo. Ther. 9 433, 1976). P reparation of 2-amino-5-bromo-6-phenyl-4-pyrimidinol (V, where X₃ is Br and X₁ is phenyl) has been reported (Brown and Stevens, JCS Perkin I, 1023, 1975) but no utility has been described for this material. Snell, Elias and Freeman in GB 1,223,686 (1967) disclose a variety of 5,6-disubstituted 2-amino-4-pyrimidinols, such as 2-dimethylamino-5-bromo-6-methyl -4-pyrimidinol but do not identify antiviral properties. Various 5-unsubstituted 2-amino-6-arylpyrimidinols are known (e.g., Sirakawa, Yakugaku Zasshi 80, 1542. 1960; Kulkarni et al., J. Sci and Ind. Research (India) 19C, 6-8 (1960), CA 54, 22576C; and U.S. Pat. No. 2,776,283. Diuretics and cardioregulatory properties are-described for various 2-amino and 2-substituted amino-5-aminomethyl and 5 -aryl-6-aryl-4-pyrimidinols, U.S. Pat. No. 2,704,285, U.S. Pat. No. 2,723,977 and U.S. Pat. No. 2,776,283. Again no antiviral properties were noted.

Although 2-amino-5-bromo-6-methyl-4-pyrimidinol (U.S. Pat. No. 3,956,302) exhibits useful antiviral and interferon inducing properties, we have found that its therapeutic application is limited to moderate doses since the material will crystallize in the urine and kidney of animals receiving high therapeutic dose.

The novel 2-amino-6-aryl-5-substituted pyrimidinols of this invention exhibit antiviral activity, an improved therapeutic ratio and fewer side effects and are useful in preventing and treating viral infections. The antiviral activity of many of the compounds of this invention is associated with increased production of interferon. Other compounds of this invention exhibit antiviral activity but do not induce interferon production.

BRIEF DESCRIPTION OF THE INVENTION

This invention relates to novel 6-aryl pyrimidine compounds and a broader group of 6-aryl pyrimidine compounds which have been found to be useful for treatment and prevention of viral infections and for induction of interferon production.

DETAILED DESCRIPTION OF THE INVENTION

The novel compound of the invention are represented by the formula ##STR1## wherein X₃ is equal to X, X₄, or X₅ wherein X₄ is fluoro, chloro, bromo or iodo, and X₅ is mono-, di or trihalomethyl, mon-, di or trifluoroethyl, perfluoropropyl, and wherein X is alkyl of from 1 to 3 carbon atoms, inclusive, including isomeric forms, 2 -propynyl and 2-propenyl, and X₁ is a member selected from the group consisting of

(a) phenyl, provided that when X₃ is bromo or X, X₁ is not phenyl,

(b) a morosubstituted phenyl of the formula ##STR2## wherein one of the groups R, R₁, R₂, R₃, R₄ is not hydrogen and wherein R or R₄ is alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms, alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms, fluoro, chloro, bromo, iodo or nitro; R₁ or R₃ is fluoro, chloro, bromo, iodo, nitro; trifluoromethyl or alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms, alkoxyethyloxy wherein alkoxy is from 1 to 5 carbon atoms, inclusive, including isomeric forms, or ##STR3## wherein R₅ and R₆ are the same or different and are alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms, benzyl, or taken together with --N> are a saturated cycloalkylamino group ##STR4## wherein n' is 3, 4, 5 or 6 or dialkyl substituted cycloalkylamino wherein each alkyl is from 1 to 3 carbon atoms, inclusive; including isomeric forms, and R₂ is chloro, fluoro, bromo, iodo, or alkyl of from 1 to 3 carbon atoms, inclusive;

(c) a disubstituted phenyl of the formula: ##STR5## wherein any two of R, R₁, R₂, R₃ and R₄ are not hydrogen and are the same or different and are fluoro, chloro, bromo, iodo, alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms, alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms, nitro and trifluoromethyl;

(d) a trihalo substituted phenyl wherein halo is chloro, bromo, iodo, or fluoro;

(e) α-naphthyl of the formula: ##STR6## wherein R₇ is substituted in either ring and is hydrogen, alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms, alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms, fluoro, chloro, iodo, bromo or nitro- provided that when X₃ is X, X₁ is not α-napthyl;

(f) 2-furyl,

(g) 3-pyridyl,

(h) 2-pyridyl, and

(i) 2-pyrazyl, provided that when X₃ is X, 2-propynyl or 2-propenyl, X₁ is not 2-furyl, 3-pyridyl, 2-pyridyl or 2-pyrazyl, or a salt thereof.

The novel compounds of this invention are prepared from β-keto ester compounds. The starting β-keto esters are prepared as follows.

A four step procedure starting with a compound of the formula Ia wherein Z is alkyl of from 1 to 5 carbon atoms, inclusive, including isomeric forms, or ##STR7## wherein R₁₀, R₁₁ and R₁₂ are the same or different and are alkyl of from 1 to 5 carbon atoms, inclusive, including isomeric forms or phenyl; and X and X₁ are as defined above. ##STR8##

Although the reaction sequence is set forth as four steps for clarity, from the chemists point of view the reaction is "one-step" in that the sequence takes place in a single reaction vessel without requirement for separation and purification after each reaction.

In step 1 the starting material, monoalkyl malonate, preferably monoethylmalonate Ia (Z=C₂ H₅), is treated in dry solvent with two equivalents of lithium base at reduced temperature.

Dry solvents can be, for example, tetrahydrofuran, diglyme, glyme, dioxane, hexamethylphosphoric triamide, or dimethyl formamide.

By lithium base is meant for example compounds of the formula R₈ --Li wherein R₈ is n-butyl, methyl, phenyl, t-butyl, s-butyl or tiN(R₉)₂ wherein R₉ is isopropyl, cyclohexyl, and trimethylsilyl or a combination thereof. n-Butyl lithium is preferred.

By reduced temperature is meant From 0° C. to -80° C. with a starting temperature of about -70° C. preferred.

Following the addition of the lithium base, with concommittent rise in temperature, the reaction mixture is recooled to about -65° C. whereupon an acid halide ##STR9## is added (Step 2). The acid halide can be added either neat or diluted with dry solvent. Dropwise addition of acid halide in dry solvent at about -65° C. is preferred.

The optimum ratio of melonate to acid halide is 1.7 (or greater) for highest yields. Acylation (step 2) and

decarboxylation (step 3) to afford Id is hastened by allowing the reaction temperature to warm slowly to room temperature.

Step 4i or work up procedure simply involves quenching the reaction a the appropriate time with dilute acid followed by extraction with ether. The organic phase is washed with bicarbonate, dried, and concentrated to yield the desired β-ketoester, IIi.

Alternatively, in step 4ii (X is not hydrogen), at least one equivalent of X-chloride, -bromide, or -iodide (preferably X-bromide or X-iodide) is added at room temperature and the reaction mixture allowed to stand until the alkylation is complete. If desired, the mixture may be warmed to hasten the alkylation. The mixture is then quenched with dilute acid, extracted with ether and the ether phase washed and concentrated, as described for step 4i, to yield the desired α-substituted β-keto ester, IIii. If desired, IIii may be further purified by conventional methods such as chromatography, distillation, and the like.

EXAMPLES Example 1 Ethylisobutyryl Acetate

To a 1 liter, 3-necked round-bottom flask, fitted with a nitrogen inlet thermometer, and an overhead stirrer is added 19.8 g. (147 mM) of monoethylmalonate, 350 ml. of dried THF and 2 rag. of bipyridyl. The solution is cooled to -70° C., and a 1.6M solution of n-butyllithium in hexane (Foote Chemicals Co. or Aldrich Chemical Co.) is added, dropwise at -70° C. to -5° C. until a pink color persisted. The temperature is allowed to slowly rise to -5° C., throughout the butyllithium addition, during which time the pink color formed will dissipate. After the pink color remains for five minutes at -5° C. (approx. 210 ml. of butyllithium has been added), the mixture is cooled to -65° C., and 7.9 ml. (7.98 g. 75 mM) of isobutyryl chloride is added dropwise at -60° C. to -65° C. The solution is stirred vigorously at -60° C. to -65° C., for 5 minutes and poured into 500 ml. of ether+300 ml. of ice-cold 1N hydrochloric acid. After shaking, the layers are separated and the organic layer is washed 2×150 ml. saturated aqueous sodium bicarbonate 1×150 ml. water and dried over sodium sulfate (anhyd.). The ethereal solution is filtered, the solids washed with ether and the combined flitrates evaporated to dryness to yield 11.7 g. (98.4%) of ethylisobutyryl acetate, m.w. 158.19.

NMR (CDCl₃):δ 4.38-4 (q, 2H, O--CH₂ --CH₃), 3.5 (s, 2H, ##STR10## 2.96-2.41 (m, 1H, CH(CH₃)₂, 1.46-1 (m, 9H, CH₃).

GLPC R.T.=3.2 min (T=90°, 3', 3% OV 17)

GC/MS M⁺ m/e 159 (27%), 116 (100%).

Example 2 Ethyl-n-butyryl Acetate

Following the procedure for the preparation of ethylisobutyryl acetate but substituting 7.98 g. (75 mM) of n-butyryl chloride in 50 ml. of dried THF for the 7.9 ml. of isobutyryl chloride, 11.4 g. (96.6%) of ethyl n-butyry) acetate is isolated, m.w. 158.19.

NMR (CDCl₃):δ 4.38-4.0 (q, 2H, OCH₂), 3.43 (s, 2H, COCH₂ CO), 2.65-2.41 (m, 2H, ##STR11## 1-91-0.78 (m, 10H, CH₃ CH₂ CH₂ C, CH₃ CH₂ O)

GLPC R.T.=3.1 min (T=90°, 3', 3% OV 17)

Example 3 Ethylpropionyl Acetate

Following the procedure for the preparation of ethylisobutyryl acetate but substituting 71. g. of monoethylmalonate (0.613M), 1300 ml. of THF and 28.1 g. of propionyl chloride (0.305M) in 300 ml. THF (added dropwise) to yield 42.0 g. (95.2%) of ethylpropionyl acetate as an oil, m.w. 144.17.

NMR (CDCl₃):δ 4.36-4 (q, 2H, O--CH₂ --CH₃), 3.41 (s, 2H, ##STR12## 2.75-2.38 (q, 2H COCH₂), 1.5-0.86 (m, 5H, CH₃).

GLPC R. T.=5.6 min (90°, 6', 3% OV 17)

GC/MS M⁺ m/e (76.5%), 115 (100%)

Example 4 Ethylphenylacetyl Acetate

Following the procedure for the preparation of ethyl-isobutyryl acetate but substituting 10.0 ml. (11.69 g. 75 mM) of phenylacetylchloride (Aldrich Chem. Co.) for the 7.9 ml. of isobutyrl chloride gave 15.4 g. (98.8%) of ethyl phenylacetyl acetate, m.w. 206.23.

NMR (CDCl₃):δ 7.38-13 (m, 5H, Ar), 4.31-3.95 (q, 2H OCH₂) 3.78 (s 2H CH₂), 3.38 (s 2H, ##STR13## 1.33-1.11 (t, 3H, CH₃).

Example 5 Ethylbenzoyl Acetate

Following the procedure for the preparation of ethyl-isobutyryl acetate but substituting 6.06 g. of monoethylmalonate (45 mM), 250 ml. THF and 2.64 ml. of benzoylchloride (3.15 g.≈2.55 mM) and stirring the reaction mixture at -65° for 60 minutes gave 4.18 g. (97%) of ethylbenzoyl acetate as an oil, m.w. 192.21. This material was isolated as a mixture of tautomers (H'-NMR).

NMR (CDCl₃):δ8.06-7.25 (m, 5H, Ar), 5.66 (s, 0.2H, ##STR14## 4.43-3.96 (m, 3.9H, OCH₂ CH₃, COCH₂ CO), 1.45-1.11 (m, 3H, CH₃).

GLPC R.T.=3.1 min (85°, 60 cm, UCW-98-2)

GC/MS M⁺ m/e 192 (6.8%), 105 (100%).

Example 6 Ethyltoluoyl Acetate

Following the procedure for the preparation of ethyl benzoyl aceatate but substituting 15.5 g. of monoethyl-malonate (115 mM), 500 ml. THF and 11.1 g. (71.8 mM) of toluoyl chloride gave 13.44 g. (90.8%) of ethyl toluoyl acetate as an oil. H'-NMR indicates the desired product is a mixture of tautomers, m.w. 206.23.

NMR (CDCl₃):δ 8.05-7.61 (m, 2H, 2,6-ArH), 7.41-7.13 (m, 2H, 3,5-ArH) 5.63 (s, 0.15H, ##STR15## 4.41-4.03 (m 2H, CH₂ CH₃), 3.95 (s 1.6H ##STR16## 2.4 (s 3H, ARCH₃), 1.43-1.11 (m, 3H, CH₂ CH₃).

Example 7 Ethylanisoyl Acetate

Following the procedure for the preparation of ethylbenzoyl acetate but substituting 15.5 g. of monoethyl malonate (115 mM), 400 ml. of THF and 12.24 g. (71.8 mM) of anisoyl chloride gave 14.45 g. (90.3%) of ethylanisoyl acetate as an oil, m.w. 222.23.

NMR (CDCl₃):δ 8.03-7.86 (m, 2H, 2,6-ArH), 7.08-6.86 (m, 2H, 3,5-ArH), 4.38-3.85 (m, 7H, OCH₃, COCH₂ CO, OCH₂ CH₃), 1.36-1.13 (t, 3H, CH₂ CH₃).

Example 8 Ethyl-p-Chlorobenzoyl Acetate

Following the procedure for the preparation of ethylbenzoyl acetate but substituting 15.5 g. of monoethylmalonate (115 mM), 400 ml. THF and 12.5 g. (71.5 mM) of p-chlorobenzoyl chloride gave 15.56 g. (95.6%) of ethyl p-chlorobenzoyl acetate as a solid. Recrystallization of an analytical sample from methanol gave solid ethyl-p-chlorobenzoyl acetate as a mixture of tautomers, m.w. 226.65.

NMR (CDCl₃):δ 7.95-7.21 (m 4H-ArH) 5.61 (s, 0.27H, ##STR17## 4.41-4 (m, 2H, CH₂ CH₃), 3.9 (s, 1.36H, COCH₂ CO), 1.43-1.1 (m, 3H, CH₂ CH₃).

Analysis:

Calc'd. for C₁₁ H₁₁ C10₃ :

C, 58.28; H, 4.89; Cl, 15.64.

Found: C, 58.34; H, 5.13; Cl, 15.32.

Example 9 Ethyl 3,4-Dichlorobenzoyl Acetate

Following the procedure for the preparation of ethyl benzoyl acetate but substituting 15.5 g. (115 mM) of monoethylmalonate, 400 ml. of THF, and 12.0 g. (57.5 mM) 3,4-dichlorobenzoyl chloride gave 14.56 g. (97%) of ethyl 3,4-dichlorobenzoyl acetate. This material slowly crystallized on standing at -12° C. and was isolated as a mixture of tautgreets, m.w. 261.1.

NMR (CDCl₃):δ 8.06-7.5 (m, 3H, ArH), 5.63 (s, 0.3H, ##STR18## 4.4-4.03 (m 2H, CH₂ CH₃), 3.93 (s 1.42H COCH₂ CO), 1.46-1.13 (m, 3H, CH₂ CH₃).

Analysis:

Calc'd. for C₁₁ H₁₀ Cl₂ O₃ : C, 50.59; H, 3.86.

Found: C, 50.21, H, 4.79.

Example 10 Ethyl-α-ethyl-benzoylacetate

To 13.2 g. of monoethylmalonate was added 300 ml. THF and 5 mg. of bipyridyl. Butyl lithium was added at -70° C. to -10° C. until a pink color persisted. The reaction mixture was recooled to -70° C. and 6.4 ml. of benzoyl chloride (0.06M) was added. After stirring at -60° C. for 60 minutes, 28.2 g. (0.182M) of ethyl idodide was added and the reaction mixture allowed to stir, at ambient temperature, for 18 hours. The mixture was then warmed to 50° C. and kept at 50° C. for 90 hours. At this time the entire mixture was poured into 500 ml. diethyl ether +300 ml. 1N hydrochloric acid, the layers separated, and the organic layer washed one time IN hydrochloric acid, once in saturated aqueous sodium bicarbonate and once with water. Drying over sodium sulfate (anhyd.), filtering and evaporating yielded 13.6 g. of ethyl α-ethyl-benzoyl -acetate as an oil.

NMR: 8.11-7.91 (m, 2H, .0.)), 7.66-7.30 (m, 3H, .0.), 4.35-3.96 (m, 3H, COCHCO, OCH₂ CH₃), 2.30-1.80 (m, 2H, CH₂ CH₃), 1.43-0.76 (m, 6H, CH₃).

The novel compounds of this invention are represented by the formula: ##STR19##

The compounds can exist in tautomer form and can be depicted as follows: ##STR20##

The pyrimidine compounds can also be named as isocytosines, e.g, 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol can also be named 5-bromo-6-m-fluorophenyl isocytosine.

The novel pyrimidines (V) can be prepared according to the following manner from the previously described β-keto esters: ##STR21## The condensation of the appropriate β-keto ester IIii with guanidine (III) can be carried out in polar solvents such as ethanol, isopropanol, 1-butanol, dimethylformamide (DMF), and the like, with ethanol preferred, in the presence of a base such as a carbonate (for example, sodium carbonate or guanidium carbonate itself) or an alkoxide (such as sodium ethoxide) and the like, under reflux in the usual manner. The product V (wherein X₃ is X₁ or X₅) is isolated by neutralization with acid or carbon dioxide of the reaction mixture after condensation is complete as determined by TLC, and filtration or chromatography in the conventional manner.

The preparation of V (wherein X₃ is X₄) is carried out from an appropriate β-keto ester IIi and guanidine (III) as described above to yield IV in like manner. Subsequent halogenation of IV for example by treatment with N-chlorosuccinimide in acetic acid to yield V wherein X₃ =X₄ =Cl, or for example by treatment with bromine in acetic acid to yield V wherein X₃ =X₄ =Br, or for example by treatment with an equivalent of 1N sodium hydroxide followed by iodine in chloroform to yield V wherein X₃ =X₄ =I, can be carried out to afford the novel pyrimidines V wherein X₃ =X₄. Alternative methods of halogenation are illustrated in the following procedures. The final pyrimidines can be isolated by concentration in vacuo and aqueous trituration of the residue followed by filtration of the resultant solid.

Example 11

General procedure and preparation of pyrimidines of the formula: ##STR22##

The compounds prepared and the procedure used are shown in Table 1.

Procedure 1

Condensation to IV or V (X₃ =X or X₅)

To 20 mM of powdered quanidine carbonate was added, under nitrogen, 120 ml. of absolute ethanol and 20 ml. of toluene. The reaction mixture was heated to reflux and 50 ml. of solvent was distilled off. The mixture was cooled to 45° C. and 40 mM of β-ketoester (II or IIii) added. This mixture was heated to reflux, with stirring, until the reaction appeared complete by TLC. Water (50 ml.) was added and the refluxing continued for an additional 30 minutes, at which time the reaction mixture was cooled to 20° C. and neutralized by addition of dry carbon dioxide or 1N aqueous hydrochloric acid. The mixture was allowed to cool at 5° C. for 18 hours, filtered and the resulting precipitate washed well with water followed by diethyl ether. The solids were dried at 60° C. under vacuum to yield the desired pyrimidine as a white solid. If the crude solids were not analytically pure they could be recrystallized from appropriate solvents, such as aqueous DMF, aqueous ethanol, and the like.

Procedure 2 Condensation

The reaction was carried out exactly as described in Procedure 1, except, after neutralization (addition of carbon dioxide or 1N hydrochloric acid) the aqueous mixture was evaporated to dryness under vacuum and 100 ml. of water and 100 ml. ethyl ether were added. The mixture was shaken and allowed to sit at 5° C., for 18 hours. The mixture was filtered and solids washed well with water followed by ethyl ether. Drying and crystalization as described in Procedure 1 gave analytically pure pyrimidine.

Procedure 3 Bromination (wherein X₃ =Br)

To 15 mM of the appropriate pyrimidine was added 80 ml. of glacial acetic acid. The reaction mixture was warmed to 50° C. to affect solution (if solids were in solution at 22° C., then it was not necessary to warm) and 0.81 ml. of Br₂ was added. The solution was allowed to stir at ambient temperature for 3 hours. The reaction was evaporated to dryness, under vacuum, and, to the resulting solids was added 150 ml. of hot water, The slurry was heated to reflux and allowed to cool to 22° C. The solids were filtered and washed well with water. The solids were pulverized and reheated with 150 ml. of water as described previously. This procedure was repeated. The pyrimidine was dried in a vacuum oven at 60° C. to give analytically pure material. If desired, it can be recrystallized from water:DMF by adding DMF slowly to a stirring slurry of compound in 150 ml. of boiling water until solution occurs. Cooling and filtering yielded analytically pure material.

Procedure 4 Bromination (wherein X₃ =Br)

To 15 mM of the appropriate pyrimidine was added 50 ml. of water and 0.66 g. of NaOH (16.5 mM). The solution was allowed to stir at ambient temperature for 30 minutes and 0.9 ml. of Br₂ (22.62 g. 16.5 mM) in 50 ml. of chloroform was added. The reaction mixture was stirred, vigorously, for 2 hours and filtered. Solids were washed well with water, followed by water and dried at 60° C. in a vacuum oven for 18 hours. Recrystallization from water:DMF as per Procedure 3 gave analytically pure material.

Procedure 5 Iodination (wherein X₃ =I)

To 15 mM of the appropriate pyrimidine was added 50 ml. of water and 0.80 g. (20 mM) of sodium hydroxide. The mixture was stirred and heated to 50° C. until solution occurred. A slurry of 3.79 g. of powdered I₂ (15 mM) in 100 ml. of chloroform was added. The excess I₂ was washed into the reaction vessel with an additional 30 ml. of chloroform. The mixture was allowed to stir, vigorously, at ambient temperature for four hours.

The solids were filtered, washed well with water (until water was neutral to pH paper) followed by either acetone or ethyl acetate until the organic wash was colorless. It is often desirable to pulverize the solids before washing. The solids were dried at 60° C. in a vacuum oven. If material is not analytically pure it may be recrystallized from water:DMF by adding DMF slowly to a vigorously stirring slurry of the pyrimidine in 150 ml. of boiling water until solution occurs. Cooling, filtering and drying at 60° C. gives analytically pure material.

Procedure 6 Iodination (X₃ =I)

To 1.95 mM of the appropriate pyrimidine was added 25.0 ml. of glacial acetic acid and 434 mg. (2 mM) of N-iodosuccinimide. The reaction mixture was allowed to stir at ambient temperature for 5 days. The mixture was evaporated to dryness under vacuum at 50° C. The solids were purified by heating with 50 ml. of absolute ethanol at reflux and cooling to room temperature. Filtering and washing with absolute ethanol gave the pure 5-iodo-pyrimidine.

Procedure 7

Chlorination (X₃ =Cl)

To 0.1M of a 6-arylpyrimidine was added 500 ml. of glacial acetic acid and 14.6 g. of N-chlorosuccinimide (0.11M). The reaction mixture was heated on a steam bath for 11/2 hours. The reaction mixture was cooled to 22° C., evaporated to a volume of 200 ml. and filtered. The solids thus obtained were washed with glacial acetic acid followed by ethyl ether and dried at 60° C. in a vacuum oven. If the solids are not analytically pure, they can be recrystallized from water:DMF by adding DMF to a boiling slurry of the pyrimidine in 500 ml. water until solution occurred. Cooling and filtering gives an analytically pure 5-chloro-6-arylpyrimidine.

Procedure 8 Fluorination (X₃ =F)

The introduction of fluorine into the 5-position of the pyrimidine ring is effected by fluorination of IV with trifluoromethylhypofluorite followed by base according to the procedure of M. J. Robbins and S. R. Naik, J. Am. Chem. Soc. 93, 5277 (1971). Alternatively, if desired, IV may be fluorinated directly with fluorine-pyridine complex to produce V where X₃ =F by the procedure described by H. Meinert and D. Cech, Z. Chem. 12, 292 (1972).

Procedure 9 Preparation of V (X₃ =CF₃)

Preparation of V wherein X₃ =CF₃ may be achieved starting with V wherein X₃ =I by the exchange procedures described by D. Cech, R. Wohlfeil and G. Efzold, Nucleic Acids Research 2, 2183. (1975) and by Y. Kobayashi, I. Kumadaki and F. Yamamato J.C.S. Chem. Comm. 536 (1977) using trifluoromethyliodide and copper-bronze. In like manner, 5-perfluoroalkylpyrimidines (V, X₃ =perfluoroalkyl) may be prepared using perfluoroalkyl iodides.

Alternatively, if desired, the trifluoromethyl or perfluoroalkyl group can be introduced earlier at the β-ketoester stage and the resulting trifluoromethyl or perfluoroalkyl β-ketoester condensed with guanidine as in Procedures 1 or 2 to produce V (X₃ =CF₃ or perfluoroalkyl). Preparation of a trifluoromethyl or perfluoromethyl, β-ketoester may be achieved by methods known in the art. For example, condensation of ##STR23## and CH₂ =CF₂ in the presence of SbF₅ affords and carboalkoxylation under standard conditions yields ##STR24##

Procedure 10 Preparation of V (X₃ =CH₂ --X₄)

Preparation of V wherein X₃ =CH₂ X₄ can be accomplished under standard conditions known in the art from the corresponding hydroxymethyl (V, wherein X₃ =CH₂ OH) intermediates. These intermediates can be prepared under standard conditions from IV and formaldehyde or alternatively from a suitably protected β-ketoester, for example ArCOCH(CH₂ OCH₂ .0.)CO₂ E_(t), itself prepared from I by the previously described chemistry wherein X is --CH₂ OCH₂ .0.. Hydrogenylitic or protolyric removal of the benzyl group will yield V wherein X₃ =CH₂ OH, after condensation of the β-ketoester with guanidine as described in Procedure 1. The resulting 5-hydroxymethylpyrimidine is transformed into the corresponding 5-halomethylpyrimidine by standard procedures known in the art, either via displacement reactions on the corresponding 5-tosyloxymethyl derivative (formed with toluensulfonyl chloride in pyridine) with alkali or alkaline earth halogen salts, or directly with the known phosphine--carbon tetrahalide methodology.

    __________________________________________________________________________                       Procedure                                                    X.sub.3  X.sub.1  No..sup.a                                                                            C  H  N  F  Cl Br I                                    __________________________________________________________________________                             CALCULATED                                             Cl       φ    7     54.19                                                                             3.63                                                                              18    15.99                                                              FOUND - m.p., other.sup.b                                                      54.64                                                                             3.75                                                                              19.15 15.38                                                              CALCULATED                                             Br       φ    3     45.13                                                                             3.03                                                                              15.79    30.03                                                           FOUND - m.p., other.sup.b                                                      45.20                                                                             3.00                                                                              15.66    29.92                                                           CALCULATED                                             I        φ    5     38.36                                                                             2.57                                                                              13.42       40.53                                                        FOUND - m.p., other.sup.b                                                      38.46                                                                             2.57                                                                              13.28       39.74                                                        CALCULATED                                             CH.sub.3  φ   1     65.65                                                                             5.51                                                                              20.88                                                                    FOUND - m.p., other.sup.b                                                      65.52                                                                             5.38                                                                              20.86                                                                    CALCULATED                                             CH.sub.3 CH.sub.2                                                                       φ    1     66.95                                                                             6.08                                                                              19.52                                                                    FOUND - m.p., other.sup.b                                                      66.63                                                                             5.94                                                                              19.63                                                                    CALCULATED                                             Br       4-CH.sub.3 φ .HBr                                                                   3     36.59                                                                             2.79                                                                              11.63    44.27                                                           FOUND - m.p., other.sup.b                                                      37.48                                                                             3.18                                                                              12.01    43.36                                                           CALCULATED                                             I        4-CH.sub.3 φ                                                                        5     40.38                                                                             3.08                                                                              12.84       38.80                                                        FOUND - m.p., other.sup.b                                                      40.32                                                                             3.19                                                                              12.93       38.14                                                        CALCULATED                                             Br       4-Cl φ                                                                              3      39.96                                                                            2.34                                                                              13.98 11.79                                                                             26.59                                                           FOUND - m.p., other.sup.b                                                      39.92                                                                             2.38                                                                              14.12 10.65                                                                             27.87                                                           CALCULATED                                             Cl       3-F φ                                                                               7     50.12                                                                             2.95                                                                              17.53                                                                             7.93                                                                              14.80                                                              FOUND - m.p., other.sup.b                                                      50.16                                                                             2.90                                                                              17.43                                                                             7.84                                                                              14.40                                                              CALCULATED                                             Br       3-F φ                                                                               3     42.27                                                                             2.48                                                                              14.79                                                                             6.68  28.13                                                           FOUND - m.p., other.sup.b                                                      42.24                                                                             2.47                                                                              14.73                                                                             6.74  28.15                                                           CALCULATED                                             I        3-F φ                                                                               5     36.27                                                                             2.13                                                                              12.64                                                                             5.74     38.73                                                        FOUND - m.p., other.sup.b                                                      36.30                                                                             2.18                                                                              12.65                                                                             5.59     38.10                                                        CALCULATED                                             Br       3-Br φ                                                                              3     34.81                                                                             2.04                                                                              12.18    46.32                                                           FOUND - m.p., other.sup.b                                                      34.78                                                                             1.78                                                                              12.15    45.72                                                           CALCULATED                                             I        3-Br φ                                                                              5     30.64                                                                             1.80                                                                              10.72    20.38                                                                             32.07                                                        FOUND - m.p., other.sup.b                                                      30.95                                                                             1.89                                                                              11.05    20.54                                                                             32.06                                                        CALCULATED                                             Cl       3-I φ                                                                               7     34.56                                                                             2.03                                                                              12.09 10.20 36.51                                                        FOUND - m.p., other.sup.b                                                      34.55                                                                             1.94                                                                              11.77 10.54 36.2                                                         CALCULATED                                             Br       3-I φ                                                                               3     30.64                                                                             1.80                                                                              10.72    20.39                                                                             32.37                                                        FOUND - m.p., other.sup.b                                                      30.86                                                                             1.94                                                                              10.90    20.10                                                                             32.08                                                        CALCULATED                                             I        3-I φ                                                                               5     27.33                                                                             1.60                                                                               9.57       57.82                                                        FOUND - m.p., other.sup.b                                                      27.58                                                                             1.77                                                                               9.62       56.22                                                        CALCULATED                                             Cl       3-CH.sub.3 O φ                                                                      7     52.58                                                                             3.98                                                                              16.73 13.94                                                              FOUND - m.p., other.sup.b                                                      52.22                                                                             3.95                                                                              16.65 13.91                                                              CALCULATED                                             Br       3-CH.sub.3 O φ                                                                      3     44.59                                                                             3.40                                                                              14.19    26.99                                                           FOUND - m.p., other.sup.b                                                      44.22                                                                             3.62                                                                              14.11    26.59                                                           CALCULATED                                             I        3-CH.sub.3 O φ                                                                      5     38.51                                                                             2.94                                                                              12.25       36.98                                                         FOUND - m.p., other.sup.b                                                     38.78                                                                             3.03                                                                              12.16       36.85                                                        CALCULATED                                             Br       3-NO.sub.2 φ                                                                        3     38.61                                                                             2.27                                                                              18.01    25.68                                                           FOUND - m.p., other.sup.b                                                      38.71                                                                             2.23                                                                              18.23    25.75                                                           CALCULATED                                             I        3-NO.sub.2 φ                                                                        5     33.54                                                                             1.97                                                                              15.65       35.44                                                        FOUND - m.p., other.sup.b                                                      31.97                                                                             1.91                                                                              14.96       32.57                                                        CALCULATED                                             Br       3-CF.sub.3 φ                                                                        3     39.54                                                                             2.11                                                                              12.57                                                                             17.06 23.92                                                           FOUND - m.p., other.sup.b                                                      39.79                                                                             2.02                                                                              12.80                                                                             17.04 24.11                                                           CALCULATED                                             I        3-CF.sub.3 φ                                                                        5     34.66                                                                             1.85                                                                              11.02                                                                             14.95    33.30                                                        FOUND - m.p., other.sup.b                                                      34.65                                                                             1.47                                                                              11.22                                                                             14.87    33.39                                                        CALCULATED                                             H        α-naphthyl                                                                        1     70.87                                                                             4.67                                                                              17.71                                                                    FOUND - m.p., other.sup.b                                                      70.76                                                                             4.76                                                                              17.49                                                                    CALCULATED                                             Br       α-naphthyl                                                                        3     53.18                                                                             3.19                                                                              13.29    25.27                                                           FOUND - m.p., other.sup.b                                                      53.05                                                                             3.24                                                                              12.71    25.23                                                           FOUND - m.p., other.sup.b                                                      45.53                                                                             2.87                                                                              19.56 17.33                                                              CALCULATED                                             Br       2-furyl  4     37.52                                                                             2.35                                                                              16.41    31.20                                                           FOUND - m.p., other.sup.b                                                      36.66                                                                             2.41                                                                              16.10    32.39                                                           CALCULATED                                             I        2-furyl  5     31.70                                                                             2.00                                                                              13.87                                                                    FOUND - m.p., other.sup.b                                                      33.10                                                                             1.94                                                                              14.40                                                                    CALCULATED                                             I        α-naphthyl                                                                        5     46.30                                                                             2.77                                                                              11.57       34.95                                                        FOUND - m.p., other.sup.b                                                      46.54                                                                             2.90                                                                              11.41       34.88                                                        CALCULATED                                             CH.sub.3 α-naphthyl                                                                        1     71.69                                                                             5.21                                                                              16.72                                                                    FOUND - m.p., other.sup.b                                                      70.91                                                                             5.34                                                                              16.75                                                                    CALCULATED                                             Cl       2-furyl  7     45.40                                                                             2.85                                                                              19.86 16.75                                                              CALCULATED                                             I        4-Cl φ                                                                              5     34.56                                                                             2.03                                                                              12.09 10.20 36.52                                                        FOUND - m.p., other.sup.b                                                      35.00                                                                             2.29                                                                              12.46 10.64 35.02                                                        CALCULATED                                             Br       3,4-Cl.sub.2 φ .HBr                                                                 3     28.87                                                                             1.45                                                                              10.10 17.05                                                                             38.43                                                           FOUND - m.p., other.sup.b                                                      29.68                                                                             1.77                                                                              10.86 16.64                                                                             38.28                                                           CALCULATED                                             I        3,4-Cl.sub.2 φ                                                                      5     31.44                                                                             1.58                                                                              11.00 18.56 33.22                                                        FOUND - m.p., other.sup.b                                                      31.27                                                                             1.65                                                                              10.99 17.07 35.43                                                        CALCULATED                                             Br       3,5-Cl.sub.2 φ                                                                      3     35.85                                                                             1.80                                                                              12.54 21.17                                                                             23.85                                                           FOUND - m.p., other.sup.b                                                      36.07                                                                             1.82                                                                              12.69 20.18                                                                             25.85                                                           CALCULATED                                             I        3,5-Cl.sub.2 φ                                                                      5     31.44                                                                             1.58                                                                              11.00 18.56 33.22                                                        FOUND - m.p., other.sup.b                                                      31.12                                                                             1.50                                                                              10.75 19.20 28.11                                                        CALCULATED                                             Cl       2,5-Cl.sub.2 φ                                                                      7     41.33                                                                             2.08                                                                              14.46 36.61                                                              FOUND - m.p., other.sup.b - 260-280d                                           41.54                                                                             2.18                                                                              14.63 36.50                                                              CALCULATED                                             Br       2,5-Cl.sub.2 φ                                                                      3                                                                                    FOUND - m.p., other.sup.b - 255-275d                                           CALCULATED                                             I        2,5-Cl.sub.2 φ                                                                      5     31.44                                                                             1.58                                                                              11.00                                                                    FOUND - m.p., other.sup.b - 180-181                                            31.54                                                                             1.62                                                                              10.98                                                                    CALCULATED                                             Cl       3-Cl φ                                                                              7     46.90                                                                             2.75                                                                              16.41 27.69                                                              FOUND - m.p., other.sup.b                                                      46.95                                                                             2.67                                                                              16.54 27.91                                                              CALCULATED                                             Br       3-Cl φ                                                                              3     39.96                                                                             2.34                                                                              13.98 11.79                                                                             26.59                                                           FOUND - m.p., other.sup.b                                                      40.33                                                                             2.40                                                                              14.00 11.62                                                                             26.99                                                           CALCULATED                                             I        3-Cl φ                                                                              5     34.56                                                                             2.03                                                                              12.09 10.20 36.52                                                        FOUND - m.p., other.sup.b                                                      34.80                                                                             2.12                                                                              12.12  9.93 36.46                                                        CALCULATED                                             Br       2-pyridyl .HBr                                                                          3     31.06                                                                             2.32                                                                              16.10    45.93                                                           FOUND - m.p., other.sup.b                                                      30.47                                                                             3.00                                                                              16.09    45.51                                                           CALCULATED                                             I        2-pyridyl                                                                               5     34.41                                                                             2.25                                                                              17.84       40.40                                                        FOUND - m.p., other.sup.b                                                      34.49                                                                             2.39                                                                              18.06       40.25                                                        CALCULATED                                             Br       3-pyridyl                                                                               3     40.47                                                                             2.64                                                                              20.99                                                                    FOUND - m.p., other.sup.b                                                      39.89                                                                             2.66                                                                              21.85                                                                    CALCULATED                                             I        3-pyridyl                                                                               5     34.41                                                                             2.24                                                                              17.84       40.40                                                        FOUND - m.p., other.sup.b                                                      34.83                                                                             2.22                                                                              18.23       40.47                                                        CALCULATED                                             Cl       2-Cl φ                                                                              7     46.90                                                                             2.75                                                                              16.41 27.69                                                              FOUND - m.p., other.sup.b                                                      46.75                                                                             2.74                                                                              16.23 27.64                                                               CALCULATED                                            Br       2-Cl φ                                                                              3     40.00                                                                             2.35                                                                              13.98 11.80                                                                             26.69                                                           FOUND - m.p., other.sup.b                                                      49.90                                                                             2.29                                                                              14.10 11.05                                                                             28.07                                                           CALCULATED                                             I        2-Cl φ                                                                              5     34.56                                                                             2.03                                                                              12.09 10.20 35.52                                                        FOUND - m.p., other.sup.b                                                      34.36                                                                             2.09                                                                              12.16 10.75 34.75                                                        CALCULATED                                             Cl       2-CH.sub.3 φ                                                                        7     56.05                                                                             4.27                                                                              17.83    15.04                                                           FOUND - m.p., other.sup.b                                                      55.95                                                                             4.03                                                                              17.64    15.01                                                           CALCULATED                                             Br       2-CH.sub.3 φ                                                                        3     47.16                                                                             3.59                                                                              15.00    28.64                                                           FOUND - m.p., other.sup.b                                                      47.04                                                                             3.77                                                                              14.81    29.09                                                           CALCULATED                                             I        2-CH.sub.3 φ                                                                        5     40.38                                                                             3.08                                                                              12.84       38.79                                                        FOUND - m.p., other.sup.b                                                      40.10                                                                             3.04                                                                              12.73       39.05                                                        CALCULATED                                             Cl       2-CH.sub.3 O φ                                                                      7     52.49                                                                             4.01                                                                              16.70    14.09                                                           FOUND - m.p., other.sup.b                                                      52.56                                                                             4.27                                                                              16.69    13.11                                                           CALCULATED                                             Br       2-CH.sub.3 O φ                                                                      3     44.61                                                                             3.40                                                                              14.19    26.99                                                           FOUND - m.p., other.sup.b - 288-289                                            44.91                                                                             3.38                                                                              14.39    26.64                                                           CALCULATED                                             Br       2-F φ                                                                               3     42.27                                                                             2.48                                                                              14.79                                                                    FOUND - m.p., other.sup.b                                                      42.86                                                                             2.76                                                                              14.47                                                                    CALCULATED                                             I        2-F φ                                                                               5     36.27                                                                             2.13                                                                              12.69                                                                             5.73     38.33                                                        FOUND - m.p., other.sup.b                                                      36.54                                                                             2.14                                                                              12.83                                                                             5.65     38.04                                                        CALCULATED                                             Cl       2-F φ                                                                               7     50.12                                                                             1.94                                                                              17.52 14.79                                                              FOUND - m.p., other.sup.b                                                      49.82                                                                             3.00                                                                              17.13 14.48                                                              CALCULATED                                             I        4-F φ                                                                               5     36.27                                                                             2.13                                                                              12.69                                                                             5.73     38.33                                                        FOUND - m.p., other.sup.b                                                      36.11                                                                             2.15                                                                              12.53                                                                             5.63     38.03                                                        CALCULATED                                             Br       4-F φ                                                                               3     42.47                                                                             2.48                                                                              14.79                                                                              6.68                                                                 FOUND - m.p., other.sup.b                                                      41.81                                                                             2.53                                                                              14.47                                                                             6.43                                                                  CALCULATED                                             Cl       4-F φ                                                                               7     50.12                                                                             2.94                                                                              17.53 14.79                                                              FOUND - m.p., other.sup.b                                                      50.27                                                                             3.15                                                                              17.49 14.77                                                              CALCULATED                                             C.sub.2 H.sub.5                                                                         4-F φ                                                                               2     61.79                                                                             5.18                                                                              18.01                                                                             8.14                                                                  FOUND - m.p., other.sup.b                                                      60.37                                                                             5.16                                                                              18.03                                                                             8.07                                                                  CALCULATED                                             C.sub.2 H.sub.5                                                                         2-F φ                                                                               2     61.79                                                                             5.18                                                                              18.01                                                                             8.14                                                                  FOUND - m.p., other.sup.b                                                      61.59                                                                             5.12                                                                              17.85                                                                             7.94                                                                  CALCULATED                                             Cl       3,4-Cl.sub.2 φ                                                                      7     41.33                                                                              2.07                                                                             14.46 36.31                                                              FOUND - m.p., other.sup.b                                                      41.79                                                                             2.21                                                                              14.5  32.59                                                              CALCULATED                                             Cl       3-NO.sub.2 φ                                                                        7     45.04                                                                             2.64                                                                              21.01                                                                    FOUND - m.p., other.sup.b                                                      45.11                                                                             2.50                                                                              20.67                                                                    CALCULATED                                             Cl       α-naphthyl                                                                        7     61.88                                                                             3.71                                                                              15.46 13.04                                                              FOUND - m.p., other.sup.b                                                      61.08                                                                             3.76                                                                              15.18 12.73                                                              CALCULATED                                             CH.sub.2 φ                                                                          φ    1     73.62                                                                             5.45                                                                              15.15                                                                    FOUND - m.p., other.sup.b                                                      73.34                                                                             5.45                                                                              15.17                                                                    CALCULATED                                             CH.sub.3 CH.sub.2 CH.sub.2 --                                                           φ    1     68.09                                                                             6.59                                                                              18.33                                                                    FOUND - m.p., other.sup.b                                                      67.84                                                                             6.49                                                                              18.33                                                                    CALCULATED                                             CH.sub.2 ═CHCH.sub.2 --                                                             φ    1     68.70                                                                             5.76                                                                              18.49                                                                    FOUND - m.p., other.sup.b                                                      68.34                                                                             5.78                                                                              18.39                                                                    CALCULATED                                             Br       2-pyrazine                                                                              3     35.84                                                                             2.26                                                                              26.13    29.81                                                           FOUND - m.p., other.sup.b                                                      35.24                                                                             2.33                                                                              26.18    29.09                                                           CALCULATED                                             I        2-pyrazine                                                                              5     30.49                                                                             1.92                                                                              22.23       40.28                                                        FOUND - m.p., other.sup.b                                                      30.67                                                                             2.13                                                                              22.34       40.39                                                        CALCULATED                                             Cl       2-pyrazine                                                                              7     42.96                                                                             2.70                                                                              31.32 15.86                                                              FOUND - m.p., other.sup.b                                                      43.10                                                                             2.90                                                                              31.41 15.89                                                              CALCULATED                                             I        2-CH.sub.3 O φ                                                                      5     38.50                                                                             2.94                                                                              12.25       36.98                                                        FOUND - m.p., other.sup.b - 280-281                                            39.09                                                                             3.77                                                                              12.81       33.64                                                        CALCULATED                                             Cl       3,5-(CH.sub.3 O).sub.2 φ                                                            7     51.16                                                                             4.29                                                                              14.91 12.58                                                              FOUND - m.p., other.sup.b                                                      51.35                                                                             4.18                                                                              14.78 12.84                                                              CALCULATED                                             Br       3,5-(CH.sub.3 O).sub.2 φ                                                            3     44.18                                                                             3.90                                                                              12.88    24.50                                                           FOUND - m.p., other.sup.b - 0.78% H.sub.2 O                                    43.81                                                                             3.74                                                                              13.08    24.57                                                            CALCULATED                                            I        3,5-(CH.sub.3 O).sub.2 φ                                                            5     38.62                                                                             3.24                                                                              11.26       34.01                                                        FOUND - m.p., other.sup.b - 0.48% H.sub.2 O                                    37.26                                                                             3.15                                                                              11.15       34.74                                                        CALCULATED                                             I        3-C.sub.2 H.sub.5 O φ                                                               5     40.35                                                                             3.38                                                                              11.76       35.53                                                        FOUND - m.p., other.sup.b                                                      40.31                                                                             3.23                                                                              12.04       32.22                                                        CALCULATED                                             Cl       3-C.sub.2 H.sub.5 O φ                                                               7     54.24                                                                             4.55                                                                              15.81 13.34                                                              FOUND - m.p., other.sup.b - 7.5% H.sub.2 O                                     49.77                                                                             4.65                                                                              14.52 12.38                                                              CALCULATED                                             Br       3-n-C.sub.3 H.sub.7 O φ                                                             3     48.16                                                                             4.35                                                                              12.96    24.65                                                           FOUND - m.p., other.sup.b                                                      47.86                                                                             4.30                                                                              12.87 25.33                                                              CALCULATED                                             I        3-n-C.sub.3 H.sub.7 O φ                                                             5     42.06                                                                             3.80                                                                              11.32       34.19                                                        FOUND - m.p., other.sup.b                                                      42.41                                                                             3.75                                                                              11.85 33.50                                                              CALCULATED                                             Cl       3-n-C.sub.3 H.sub.7 O φ                                                             7     55.82                                                                             5.04                                                                              15.02 12.68                                                              FOUND - m.p., other.sup.b                                                      55.89                                                                             5.22                                                                              14.99 12.64                                                              CALCULATED                                             I        3-C.sub.2 H.sub.5 OC.sub.2 H.sub.4 O φ                                              5     41.90                                                                             4.02                                                                              10.47       31.63                                                        FOUND - m.p., other.sup.b                                                      40.58                                                                             3.96                                                                              10.73       32.69                                __________________________________________________________________________      .sup.a In all of the examples where X.sub.3 is halogen, the procedure          number listed refers only to the appropriate halogenation procedure and        presumes Procedure 1 or 2 has already been accomplished.                       .sup.b A majority of the products exhibit melting points that are not          necessarily a distinguishing characteristic of the compound either becaus      of decomposition or greater than 200° and are therefore not listed                                                                               

Example 12 2-Amino-6-(2-furyl)-4-pyrimidinol

To a 3-neck, 500 ml. flask fitted with a paddle stirrer, Dean-Stark trap, and a reflux condenser is added 5.76 g. of powdered guanidine carbonate (31.9 mM), 200 ml. absolute C₂ H₅ OH and 20 ml. toluene. The solution is removed azeotropically. The reaction mixture is allowed to cool to 50° C., the Dean-Stark trap removed, and 10.4 g. (64 mM) of ethyl-2-furoyl-acetate (57.07 mM) is added. The reaction mixture is heated at reflux for 18 hours; 50 ml. of water is added and heating is continued for 30 minutes. The reaction is allowed to cool to 25° C. Chips of carbon dioxide are added until the mixture is neutral and the flask is placed in the refrigerator at 5° C. under vacuum to yield 5.6 g. (49%) of pure 2-amino-6-(2-furyl)-4-pyrimidinol.

Example 13 2-Amino-6-(m-chlorophenyl)-4-pyrimidinol

To a 3-neck, 500 ml. RB flask fitted with an overhead stirrer, condenser, and Dean-Stark trap under nitrogen is added 5.76 g. (32 mmole) of powdered guanidine carbonate, 200 ml. of absolute ethanol and 20 ml. of toluene. By heating to reflux 100 ml. of solvent is removed via the trap following which the solution is cooled to approximately 50° C. and trap removed. Ethyl-m-chlorobenzoyl acetate (14.8 g., 65 mmole) is introduced into the vessel and the reaction is stirred at reflux for 17 hours. Approximately 30 ml. of water is added and heating continued for 30 minutes. The mixture is then cooled in a refrigerator for 18 hours. The precipitate is filtered and washed with ethanol followed by ether and dried at 60° C. under vacuum to yield 10.6 g. (74%) of 2-amino-6-(m-chlorophenyl )-4-pyrimidinol.

Example 14

2-Amino-6-(o-methoxyphenyl)-4-pyrimidinol

Following the procedure of Example 12 but substituting 5.67 g. (31.5 mM) of guanidine carbonate, 200 ml. of absolute ethanol, 20 ml. of toluene, 14.15 g. of ethyl-o-methoxybenzoyl acetate, and 150 hours of reflux gives 7.91 g. (57.8%) of 2-amino-6 (o-methoxyphenyl)-4-pyrimidinol as a white solid (m.p. 283.5°-284.5° C.)

Example 15

2-Amino-5-bromo-6-(m-chlorophenyl)-4-pyrimidinol

To 3.13 g. (15 mM) of 2-amino-6-(m-chlorophenyl)-4-pyrimidinol is added 80 ml. of glacial acetic acid. The solution is heated to 80° C. and 0.81 ml. of Br₂ is added. The mixture is allowed to stir at 80° C. for 15 minutes and cooled to 2.5° C. The mixture is evaporated to dryness under vacuum at 40° C. and the resulting solids heated at reflux with 150 ml. of water. The reaction mixture is cooled and filtered, and the solids washed very well with cold water. The solids are dried at 60° C. in a vacuum oven and pulverized when dry. The boiling water tritration is repeated. 3.90 G. (86.9%) of title compound is recovered. Recrystallization of the solids from water:DMF by adding DMF slowly to a stirring slurry of 3.9 g. of compound in 150 ml. boiling water until solution occurs, cooling and filtering yields analytically pure material (80% recovery).

Example 16 2-Amino-6-(m-chlorophenyl )-5-iodo-4-pyrimidinol

To 3.13 g. (15 mM) of 2-amino-6-(m-chlorophenyl)-4-pyrimidinol is added 50 ml. water +0.80 g. sodium hydroxide (20 mM). The mixture is heated to dissolve the pyrimidinol and filtered if necessary. It is cooled to 25° C. and 3.79 g. of I₂ (powdered) is added in 100 ml. chloroform. The excess 12 is washed in with 30 ml. chloroform. The reaction mixture is allowed to stir vigorously with paddle stirrer at 25° C. for 4 hours.

The reaction is filtered and the solids washed very well with water until the aqueous wash is neutral to litmus. The solids are then washed with acetone until the acetone wash is colorless. (It is desirable to pulverize the solids before washing with acetone). Drying the solids at 60° C. yields 3.50 g. (67%) of 2-amino-6-(m-chlorophenyl) -4-pyrimidinol.

Example 17 2-Amino-5-iodo-6-(2-furyl)-4-pyrimidinol

To 2.65 g. (15 mM) of 2-amino-6-(2-furyl-4-pyrimidinol is added 50 ml. water and 0.72 g. sodium hydroxide. The reaction mixture is heated to 75° C. to effect solution and then cooled to 25° C. A slurry of 4.0 g. (15.8 mM) of powdered iodine in 100 ml. chloroform is added, with vigorous stirring, and the reaction mixture is allowed to stir for 2 hours at ambient temperature. The reaction mixture is filtered. The solids are washed well with water (until wash is neutral to litmus) followed by acetone (until the acetone wash is colorless), and dried in a vacuum oven to give 3.95 g. (87%) of 2-amino-5-iodo-6-(2-furyl)-4-pyrimidinol.

Example 18 2-Amino-5-bromo-6-(2-furyl)-4-pyrimidinol

To 2.65 g. (15 mM) of 2-amino-6-(2-furyl)-4-pyrimidinol is added 50.0 ml. of water and 0.66 sodium hydroxide (16.5 mM). A cloudy solution results. The solution is allowed to stir for 30 minutes and 0.9 ml. Br₂ (2.62 g., 16.5 mM) in 20 ml. chloroform is added. The solution is allowed to stir vigorously for 2 hours and is filtered. The solids are washed well with water (until neutral to litmus) followed by acetone (until acetone is colorless) and dried at 60° C. to give 3.3 g. of 2-amino-5-bromo-6-(2-furyl)-4-pyrimidinol (86%).

Example 19 2-Amino-5-chloro-6-phenyl-4-pyrimidinol

To 1.87 g. (10 mM) of 2-amino-6-phenyl-4-pyrimidinol is added 50 ml. of glacial acetic acid and 1.46 g. (11 mM) of N-chlorosuccinimide. The mixture is heated with magnetic stirring under nitrogen at 90° C. for 2 hours (solution was complete in less than 20 minutes). The heat is removed and the amber solution is allowed to cool to room temperature. The solution is evaporated to a volume of 10 ml. under vacuum, cooled to 20° C. and filtered. The resulting solids are washed successively with CH₃ COOH (5 ml.), water (50 ml.), acetone (100 ml.) and diethyl ether (100 ml.). The solids are dried at 60° C. in a vacuum even to yield 1.40 g. (63%) of title compound. The solids can be recrystallized from ethanol:DMF by adding DMF to a hot, ethanol slurry of the pyrimidine until solution is complete. Cooling the solution at 5° C. for 18 hours filtering and drying gives analytically pure 2-amine-5-chloro-6-phenyl-4-pyrimidinol.

Example 20

2-Amino-5-iodo-6-phenyl-4-pyrimidinol

Following the procedure of Example 16 but substituting 21.4 g. (0.113M) of 2-amino-6-phenyl-4-pyrimidinol, 200 ml. water, 500 ml. chloroform, 5.6 g. sodium hydroxide and 28.8 g. I₂, a yield of 29.0 g. (78%) of 2-amino-5-iodo-6-phenyl-4-pyrimidinol is obtained.

Example 21

2-Amino-5-iodo-6-phenyl-4-pyrimidinol zinc salt

To 1.56 g. (5 mmole) of 2-amino-5-iodo-6-phenyl-4-pyrimidinol in 15 ml. of methanol under nitrogen with stirring at room temperature is added 1.1 ml. of a 25% NaOCH₃ /CH₃ OH solution. After five minutes 340 mg. (2.5 mmole) of anhydrous zinc chloride (ZnCl₂)) was added. After one hour the heterogeneous solution is concentrated to dryness, washed with 2×50 ml. water, filtered, and dried in vacuo at 60° C. for 18 hours. The product is a white solid with m.p. at 285° C.

This invention further relates to new pharmaceutical compositions and a method of preventing or treating viral infections and inducing interferon production in vivo and in vitro (tissue culture).

The present invention comprises the compositions and the method of inducing interferon production and/or preventing or treating viral infections, therapeutically and prophylactically by administration of a compound selected from the group consisting of compounds having the formula: ##STR25## wherein X₃ and X₁ are as previously defined, referred to generically as 6-aryl-pyrimidines and hereafter termed "active ingredients", or the pharmacologically acceptable acid addition salts thereof; in association with a pharmaceutical carrier.

Suitable pharmacologically acceptable acid addition salts are for example the hydrochloride, sulfate, phosphate, nitrate, and the like. These salts can be used in the same manner as the base compounds.

According to the present invention, a vital infection is treated or prevented and interferon production is increased in vivo by administering the active ingredients to a suitable host. By "host" is meant interferon producing animals, i.e., intact viable animals which are capable of interferon production. The host may be warm-blooded animals such as mammals, e.g., mice, rats, rabbits, bovine, pigs, hamsters, dogs, cats; guinea pigs, horses, goats, sheep, monkeys, man; and birds, e.g., chickens, ducks, turkeys, pigeons, parakeets, and canaries. The mode of administration can be parenterally such as subcutaneously, intramuscularly, intradermally, intraperitoneally, intrathecally, intravenously or locally, preferably on a mucous membrane such as intranasally, pharyngolaryngeally, bronchially, broncholially, intravaginally, rectally or ocularly. The mode of administration can also be by implantation. Alternatively or concurrently, administration can be by the oral route, a preferred mode of administration for an interferon inducer. Practically, it is advantageous to administer the active ingredient to the host orally, tntranasally, topically, locally, subcutaneausly or intramuscularly.

The induction of interferon by administration of an active ingredient is demonstrated by established interferon assay methods such as plaque-reduction, see Finter, Interferons and Interferon Inducers, (1973). The interferon induced by the administration of an active ingredient can also be demonstrated by the injection of the host animals as well as tissue cultures against virus challenge.

The administration of the active ingredients are also useful prophylactically and therapeutically for preventing and treating viral infections. For example, pharmaceutical compositions containing the active ingredients are useful in prophylactic or therapeutic treatment of humans and animals infected or likely to be infected with viruses, e.g., hepatitis virus, rubella, rubeolla, influenza, encephalitis viruses (i.e., arboviruses such as western or eastern equine encephalitis virus, Semliki Forest virus), herpes viruses (types 1 or 2 herpes simplex virus, cytomagalovirus, varicella-zoster and infectious bovine rhinotracheitis virus), rabies, enteroviruses (picornaviruses, echoviruses, coxsackie viruses), parainfluenza viruses, respiratory syncytial virus, sendai virus, poliomyelitis viruses, yellow fever, Epstein Barr virus (infectious mononucleosis), small pox, Dengue virus, common cold virus (rhinoviruses, coronaviruses, etc.), adenoviruses, polyomaviruses, papovaviruses, RNA-tumor viruses (e.g., Feline leukemia virus, Arian leukosis virus, Arian sarcoma viruses), B virus, Aleutians disease of mink, arena viruses, blue tongue virus of sheep, bovine viral diarrhea-mucosal disease virus, canine distemper virus, canine hepatitis virus, canine herpesvirus, equine abortion virus, infectious equine anemia virus, fowl pox virus, hog cholara virus, Marek's disease, mink enteriris virus, Newcastle disease virus, porcine enterovirus, pseudorabies virus, foot and mouth disease virus, reoviruses, and all other viruses or diseases of viral origin (for example, slowly progressing diseases that may be of viral origin such as multiplesclerosis) that are sensitive to the antiviral action of interferon or the pyrimidine antiviral agents disclosed in this patent.

Preferred compounds are:

2-amino-5-iodo-6-(3-bromophenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(3-fluorophenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(3-ethoxyethylphenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(2-methoxyphenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(2-methoxyphenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(2-methoxyphenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(3-chlorophenyl)-4-pyrmidinol;

2-amino-5-iodo-6-(3-chlorophenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(3-chlorophenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(2-fluorophenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(3-fluorophenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(2-fluorophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3-fluorophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-phenyl-4-pyrimidinol;

2-amino-5-chloro-6-phenyl-4-pyrimidinol;

2-amino-5-bromo-6-phenyl-4-pyrimidinol;

2-amino-5-chloro-6-(3-methoxyphenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(3-methoxyphenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3-methoxyphenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(2-pyridyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3,4-dichlorophenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(α-naphthyl)-4-pyrimidinol;

2-amino-5-chloro-6-(3-nitrophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3-nitrophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3-trifluoromethylphenyl)-4-pyrimidinol;

2-amino-5-ethyl-6-phenyl-4-pyrimidinol;

2-amino-5-bromo-6-(3,5-dimethoxyphenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(3-propyloxyphenyl)-4-pyrimidinol;

or the pharmaceutically acceptable acid addition salts or alkali metal or alkaline earth metal salts there of.

In addition to the anti-viral and interferon production activity disclosed, the compounds have immunoregulatory activity; for example the compounds increased antibody formation and decreased delayed hypersensitivity and are useful in the treatment of parasitic diseases, organ transplants and skin graft reject ions, and immune deficiencies including those caused as a side effect of therapy with cytotoxic agents and radiation.

The dosage administered will be dependent upon the level of interferon desired, the identity of the viral infection, the type of animal involved, its age, health, weight, kind of concurrent treatment, if any, frequency of treatment, therapeutic ratio, and tolerance.

Care must be taken in choosing dosage regimens to be used in preventing various diseases of vital origin. Since the mechanism of antiviral action of the pyrimidines is mediated through interferon and other actions, such as direct antiviral activity of the compounds or immune modulation, consideration must be given to the type of disease being treated, the condition of the host and the nature of the causative agent (is it sensitive to the antiviral action of interferon). The route of administration of the drug will depend upon such criteria. For example, an upper respiratory tract infection may be most effectively treated by intranasal administration of the drug while systemic infections would more effectively be treated by systemic injection of the drug.

Also, the timing of drug administration can be important in maintenance of antiviral activity. It is well documented [Stringfellow, D. A., Antimicrobial Agents and Chemotherapy, 11:934-992 (1977)] that the ability of animals to produce interferon in response to agents that stimulate interferon synthesis is impaired if such agents are administered in frequent (daily) dosage regimens. In contrast, when given less frequently (once a week) animals remained responsive to each injection of inducer [Stringfellow, D. A., and S. D. Weed, Am. J. Vet. Research, 38:1963-1967 (1977)]. Since interferon mediates an intracellular antiviral state that can persist for several days after interferon is cleared from the circulation, such a treatment regimen (e.g., once a week) would be suitable for treatment of infections caused by interferon sensitive viruses. Some viruses, however, are less sensitive to interferon but the pyrimidines have antiviral activity separable from the ability to induce interferon and treatment regimens that maintain appropriate levels of circulating or tissue associated drug would be more suitable for treating or preventing such infections. For example, type 1 Herpes simplex virus (HSV-1) is not as sensitive to the antiviral action of interferon as are other viruses such as Semliki forest virus (SFV). Yet, both HSV-1 and SFV infections in mice can be effectively prevented by administration of 2-amino-5-iodo-6-phenyl-4-pyrimidinol. However, for effective prevention of HSV-1, drug must be given twice a day for three consecutive days while activity against SFV is achieved with a single injection being given once a week. Therefore, care must be taken in selecting proper treatment regimens and must consider the condition of the host, the nature of the disease process and the pharmacological properties of the agent being used.

Illustratively, dosage levels of the administered active ingredients can be: intravenous, 0.1 to about 50 mg./kg.; intraperitoneal, 0.1 to about 200 mg./kg.; subcutaneous, 0.1 to about 150 mg./kg.; intramuscular, 0.1 to about 150 mg,/kg.; orally, 0.1 to about 400 mg./kg., and preferably about 1 to 200 mg./kg.; intranasal instillation, 0.1 to about 50 mg./kg.; and aerosol, 0.1 to about 50 mg./kg. of animal (body) weight.

Expressed in terms of concentration, an active ingredient can be present in the compositions of the present invention for localized use about the cutis, intranasally, pharyngolaryngeally, bronchially, broncholially, intravaginally, rectally, or ocularly in a concentration of from about 0.1 to about 50% w/w of the composition; preferably about 1 to about 20% w/w of the composition; and for parenteral use in a concentration of from about 0.5 to about 50% w/v of the composition and preferably from about 5 to about 20% w/v.

The compositions of the present invention are preferably presented for administration to humans and animals in unit dosage forms, such as tablets, capsules, pills, powders, granules, suppositories, sterile parenteral solutions or suspensions, sterile non-parenteral solutions or suspensions, and oral solutions or suspensions and the like, containing suitable quantities of an active ingredient.

For oral administration either solid or fluid unit dosage forms can be prepared.

Powders are prepared quite simply by comminuting the active ingredient to a suitably fine size and mixing with a similarly comminuted diluent. The diluent can be an edible carbohydrate material such as lactose or starch. Advantageously, a sweetening agent or sugar is present as well as a flavoring oil.

Capsules are produced by preparing a powder mixture as hereinbefore described and filling into formed gelatin sheaths. Advantageously, as an adjuvant to the filling operation, a lubricant such as talc, magnesium stearate, calcium stearate and the like is added to the powder mixture before the filling operation.

Soft gelatin capsules are prepared by machine encapsulation of a slurry of active ingredients with an acceptable vegetable oil, light liquid petrolatum or other inert oil or triglyceride.

Tablets are made by preparing a powder mixture, granulating or slugging, adding a lubricant and pressing into tablets. The powder mixture is prepared by mixing an active ingredient, suitably comminuted, with a diluent or base such as starch, lactose, kaolin, dicalcium phosphate and the like. The powder mixture can be granulated by wetting with a binder such as corn syrup, gelating solution, methylcellulose solution or acacia mucilage and forcing through a screen. As an alternative to granulating, the powder mixture can be slugged, i.e., run through the tablet machine and the resulting imperfectly formed tablets broken into pieces (slugs). The slugs can be lubricated to prevent sticking to the tablet-forming dies by means of the addition of stearic acid, a stearic salt, talc or mineral oil. The lubricated mixture is then compressed into tablets.

Advantageously the tablet can be provided with a protective coating consisting of a sealing coat or enteric coat of shellac, a coating of sugar and methylcellulose and a polish coating of carnauba wax.

Fluid unit dosage forms for oral administration such as syrups, elixirs and suspensions can be prepared wherein each teaspoonful of composition contains a predetermined amount of active ingredient for administration. The water-soluble forms can be dissolved in an aqueous vehicle together with sugar, flavoring agents and preservatives to form a syrup. An elixir is prepared by using a hydroalcoholic vehicle with suitable sweeteners together with a flavoring agent. Suspensions can be prepared of the insoluble forms with a suitable vehicle with the aid of a suspending agent such as acacia, tragacanth, methylcellulose and the like.

For parenteral administration, fluid unit dosage forms are prepared utilizing an active ingredient and a sterile vehicle, water being preferred. The active ingredient, depending on the form and concentration used, can be either suspended or dissolved in the vehicle. In preparing solutions the water-soluble active ingredient can be dissolved in water for injection and filter sterilized before filling into a suitable vial or ampule and sealing. Advantageously, adjuvants such as a local anesthetic, preservative and buffering agents can be dissolved in the vehicle. Parenteral suspensions are prepared in substantially the same manner except that an active ingredient is suspended in the vehicle instead of being dissolved and sterilization cannot be accomplished by filtration. The active ingredient can be sterilized by exposure to ethylene oxide before suspending in the sterile vehicle. Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the active ingredient.

In addition to oral and parenteral administration, the rectal and vaginal routes can be utilized. An active ingredient can be administered by means of a suppository. A vehicle which has a melting point at about body temperature or one that is readily soluble can be utilized. For example, cocoa butter and various polyethylene glycols (Carbowaxes) can serve as the vehicle.

For intranasal instillation, fluid unit dosage forms are prepared utilizing an active ingredient and a suitable pharmaceutical vehicle, water being preferred or by dry powder for insuflation.

The active ingredients can also be admixed in animal feed. The active ingredients can conveniently be prepared in the form of a food premix. The food premix can comprise an active ingredient in admixture with an edible pharmaceutical diluent such as starch, oatmeal, flour, calcium carbonate, talc, dried fish meal and the like non-toxic, orally acceptable pharmaceutical diluents. The prepared premix is then conveniently added to the regular feed.

For use as aerosols the active ingredients can be packaged in a pressurized aerosol container together with a gaseous or liquefied propellant, for example, dichlorodifluoromethane, carbon dioxide, nitrogen, propane, and the like, with the usual adjuvants such as co-solvents and wetting agents, as may be necessary or desirable.

The term "unit dosage form" as used in the specification and claims refers to physically discrete units suitable as unitary dosages for human and animal subjects, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect in association with the required pharmaceutical diluent, carrier or vehicle. The specifications for the novel unit dosage forms of this invention are dictated by and are directly dependent on (a) the unique characteristics of the active material and the particular therapeutic effect to be achieved, and (b) the limitation inherent in the art of compounding such an active material for therapeutic use in humans, as disclosed in this specification, these being features of the present invention. Examples of suitable unit dosage forms in accord with this invention are tablets, capsules, troches, suppositories, powder packets, wafers, cachets teaspoonfuls, tablespoonfuls, dropperfuls, ampuls, vials, segregated multiples of any of the foregoing, and other forms as herein described.

The active ingredients to be employed as interferon inducers and as anti-viral agents can be easily prepared in unit dosage form with the employment of pharmaceutical materials which themselves are available in the art and can be prepared by established procedures. The following preparations are illustrative of the preparation of the unit dosage forms of the present invention, but are not intended to be limiting.

Example 22 Nard-Gelatin Capsules

One thousand two-piece hard gelatin capsules for oral use, each capsule containing 100 mg. of 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol, are prepared from the following types and amounts of ingredients:

    ______________________________________                                         2-Amino-5-bromo-6-m-fluorophenylpyrimidinol,                                                              100 gm.                                             micronized                                                                     Lactose                    100 gm.                                             Corn starch                20 gm.                                              Talc                       20 gm.                                              Magnesium stearate          2 gm.                                              ______________________________________                                    

The 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol, finely divided by means of an air micronizer, is added to the other finely powdered ingredients, mixed thoroughly and then encapsulated in the usual manner.

The foregoing capsules are useful for preventing or treating vital infection and for inducing interferon formation by the oral administration of one or two capsules one to four times a day.

Using the procedure above, capsules are similarly prepared containing 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol in 50,250 and 500 mg. amounts by substituting 50 gm., 250 gm. and 50 D gm. of 2-amino-5-bromo-6-m -fluorophenyl-5-pyrimidinol for the 100 gm. used above.

Example 23 Soft Gelatin Capsules

One-piece soft gelatin capsules for oral use, each containing 250 mg. of 2-amino-5-bromo-6-m-fluorophenyl -4-pyrimidinol (finely divided by means of an air micronizer), are prepared by first suspending the compound in 0.5 ml. of corn oil to render the material capsuletable and then capsulating in the above manner.

The foregoing capsules are useful for preventing or treating viral infection and for inducing interferon formation by the oral administration of one or two capsules one to four times a day.

Example 24 Tablets

One thousand tablets, each containing 500 mg. of 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol, are prepared from the following types and amounts of ingredients:

    ______________________________________                                         2-Amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol                                                           500 gm.                                              Lactose                   75 gm.                                               Corn starch               50 gm.                                               Magnesium stearate         4 gm.                                               Light liquid petrolatum micronized                                                                        5 gm.                                               ______________________________________                                    

The 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol, finely divided by means of an air micronizer is added to the other ingredients and then thoroughly mixed and slugged. The slugs are broken down by forcing through a Number Sixteen screen. The resulting granules are then compressed into tablets, each tablet containing 500 mg. of 2-amino-5-bromo-6m-fluorophenyl-4-pyrimidinol.

The foregoing tablets are useful for preventing or treating viral infection and for inducing interferon formation by the oral administration of one or two tablets one to four times a day.

Using the procedure above, tablets are similarly prepared containing 2-amino-5-bromo-6-m-fluorophenyl-5-pyrimidinol in 250 mg. and 100 mg. amounts by substituting 250 gm. and 10 gm. of 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol for the 500 gm. used above.

Example 25 Oral Suspension

One thousand ml. of an aqueous suspension for oral use, containing in each teaspoonful (5 ml.) dose, 500 mg. of 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol, is prepared from the following types and amounts of ingredients:

    ______________________________________                                         2-Amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol,                                                           100 gm.                                             micronized                                                                     Citric acid                2 gm.                                               Benzoic acid               1 gm.                                               Sucrose                    700 gm.                                             Tragacanth                 5 gm.                                               Lemon oil                  2 gm.                                               Deionized water, q.s. 1000 ml.                                                 ______________________________________                                    

The citric acid, benzoic acid, sucrose, tragacanth and lemon oil are dispersed in sufficient water to make 850 ml. of suspension. The 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol, finely divided by means of an air micronizer, is stirred into the syrup until uniformly distributed. Sufficient water is added to make 1000 ml.

The composition so prepared is useful for preventing or treating viral infection and for inducing interferon formation at a dose of 1 tablespoonful (15 ml.) three times a day.

Example 26

A sterile aqueous suspension for parenteral injection, containing in 1 ml. 300 mg. of 2-amino-5-bromo-6-m -fluorophenyl-4-pyrimidinol, is prepared from the following types and amounts of ingredients:

    ______________________________________                                         2-Amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol,                                                           300 gm.                                             micronized                                                                     Polysorbate 80              5 gm.                                              Methylparaben              2.5 gm.                                             Propylparaben             0.17 gm.                                             Water for injection, q.s. 1000 ml.                                             ______________________________________                                    

All the ingredients, except the 2-amino-5-bromo-6-m -fluorophenyl-4-pyrimidinol, are dissolved in the water and the solution sterilized by filtration. To the sterile solution is added the sterilized 2-amino-5-bromo-6-m -fluorophenyl-4-pyrimidinol, finely divided by means of an air micronizer, and the final suspension is filled into sterile vials and the vials sealed.

The composition so prepared .s useful for preventing or treating viral infection and for inducing interferon formation at a dose of 1 milliliter (1M) three times a day.

Example 27 Suppository, Rectal and Vaginal

One thousand suppositories, each weighing 2.5 gm. and containing 150 mg. of 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol are prepared from the following types and amounts of ingredients:

    ______________________________________                                         2-Amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol,                                                           150 gm.                                             micronized                                                                     Propylene glycol           150 gm.                                             Polyethylene glycol, 4000 q.s.                                                                            2,500 gm.                                           ______________________________________                                    

The 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol is finely divided by means of an air micronizer and added to the propylene glycol and the mixture passed through a colloid mill until uniformly dispersed. The polyethylene glycol 40000 is melted and the propylene glycol dispersion added slowly with stirring. The suspension is poured into unchilled molds at 40° C. The composition is allowed to cool and solidify and then removed from the mold and each suppository foil wrapped.

The foregoing suppositories are inserted rectally or vaginally for preventing or treating viral infection and for inducing interferon formation.

Example 28 Intranasal Suspension

One thousand ml. of a sterile aqueous suspension for intranasal instillation, containing in each ml. 150 mg. of 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol, is prepared from the following types and amounts of ingredients.

    ______________________________________                                         2-Amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol,                                                           150 gm.                                             micronized                                                                     Polysorbate 80              5 gm.                                              Methylparaben              2.5 gm.                                             Propylparaben             0.17 gm.                                             Deionized water, q.s. 1000 ml.                                                 ______________________________________                                    

All the ingredients, except the 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimldinol, are dissolved in the water and the solution sterilized by filtration. To the sterile solution is added the sterilized 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol, finely divided by means of an air micronizer, and the final suspension is aseptically filled into sterile containers.

The composition so prepared is useful for preventing or treating vital infection and for inducing interferon formation by intranasal instillation of 0.2 to 0.5 ml. given one to four times per day.

Example 29 Animal Feed

One thousand grams of feed premix is prepared from the following types and amounts of ingredients:

    ______________________________________                                         2-Amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol                                                            20 gm.                                              Soybean meal              400 gm.                                              Fish meal                 400 gm.                                              Wheat germ oil             50 gm.                                              Sorghum molasses          130 gm.                                              ______________________________________                                    

The ingredients are mixed together and pressed into pellets.

The premix can be fed to laboratory animals directly, i.e., rats and mice, for preventing or treating vital infection and for induction of interferon formation.

For larger animals the premix can be added to the animal's regular feed in an amount calculated to give the desired dose of 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol. For example, one part of premix is added to 2.5 parts of a cat's regular feed to provide the desired dose of 200 mg./kg./day for a cat of 2.5 kg.

An active ingredient can also be present, as shown in Examples 30-33 in the undiluted pure form for use locally about the cutis, intranasally, pharyngolaryngeally, bronchially, broncholially or orally.

Example 30 Powder

Five hundred grams of 2-amino-5-bromo-6-m-fluoro-phenyl-4-pyrimidinol in bulk form is finely divided by means of an air micronizer. The micronized powder is placed in a shaker-type container.

The foregoing composition is useful for preventing or treating vital infection and for inducing interferon formation at localized sites by applying the powder one to four times per day.

Example 31 Oral Powder

One thousand grams of 2-amino-5-bromo-6-m-fluoro-phenyl-4-pyrimidinol in bulk form is finely divided by means of an air micronizer. The micronized powder is divided into individual doses of 250 mg. and packaged.

The foregoing powders are useful for preventing or treating vital infection and for inducing interferon formation by the oral administration of one or two powders suspended in a glass of water, one to four times per day.

Example 32 Insufflation

One thousand grams of 2-amino-5-bromo-6-m-fluoro-phenyl-4-pyrimidinol in bulk form is finely divided by means of an air micronizer.

The foregoing composition is useful for preventing or treating viral infection and for inducing interferon formation by the inhalation of 30 to 75 mg. one to four times per day.

Example 33 Hard Gelatin Capsules

One thousand two-piece hard gelatin capsules for oral use, each capsule containing 100 mg. of 2-amino-5-bromo-6-m-fluorophenyl-4-pyrimidinol, are prepared from 100 grams of 2-amino-5-bromo-6-methyl-4-pyrimidinol.

The 2-amino-5-bromo-6-methyl-4-pyrimidinol is finely divided by means of an air micronizer and encapsulated in the usual manner.

The foregoing capsules are useful for preventing or treating viral infection and for inducing interferon formation by the oral administration of one or two capsules one to four times a day.

Using the procedure above, capsules are similarly prepared containing 2-amino-5-bromo-6-m-fluorophenyl-4pyrmidinol in 50, 250 and 500 mg. amounts by substituting 50 gm., 250 gm. and 500 gm. of 2-amino-5-bromo-6-m-fluoro -phenyl-4-pyrimidinol for the 100 gm. used above.

Example 34

Following the procedure of the preceding Examples 22 through 33, inclusive, compositions are prepared substituting equivalent amounts of the pharmaceutically acceptable acid addition salts of 2-amino-5-bromo-6-m-fluoro -phenyl-4-pyrimidinol for the free base of the examples.

Example 35

Following the procedure of the preceding Examples 22 through 34, inclusive, compositions are prepared substituting equivalent amounts of

2-amino-5-iodo-6-(3-bromophenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(3-fluorophenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(2-methoxyphenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(2-methoxyphenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(2-methoxyphenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(3-chlorophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3-chlorophenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(3-chlorophenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(2-fluorophenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(3-fluorophenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(2-fluorophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3-fluorophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-phenyl-4-pyrimidinol;

2-amino-5-chloro-6-phenyl -4-pyrimidinol;

2-amino-5-bromo-6-phenyl-4-pyrimidinol;

2-amino-5-chloro-6-(3-methoxyphenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(3-methoxyphenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3-methoxyphenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(2-pyridyl)-4-pyrimidinol;

2-amino-5-iodo-5-(3,4-dichlorophenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(α-naphthyl)-4-pyrimidinol;

2-amino-5-chloro-6-(3-nitrophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3-nitrophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(3-trifluoromethylphenyl)-4-pyrimidinol;

2-amino-5-ethyl-6-phenyl-4-pyrimidinol;

2-amino-5-bromo-6-(3,5-dimethoxyphenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(3-propyloxyphenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(2,3-difluorophenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(2,3-difluorophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(2,3-difluorophenyl)-4-pyrimidinol;

2-amino-5-bromo-6-(2,5-difluorophenyl)-4-pyrimidinol;

2-amino-5-chloro-6-(2,5-difluorophenyl)-4-pyrimidinol;

2-amino-5-iodo-6-(2,5-difluorophenyl)-4-pyrimidinol;

or the pharmaceutically acceptable acid addition salts or the alkali metal or alkaline each metal salts of each of the foregoing compounds for 2-amino-5-bromo-6-m-fluorophenyl -4-pyrimidinol of each of the examples. Those compositions are useful for preventing and treating viral infection and for inducing interferon production where administered as described above and i n Examples 22 through 34, inclusive.

Example 36 Interferon induction in cats

Cats were given 2-amino-5-bromo-6-phenyl-4-pyrimidinol orally. The drug was suspended in carboxymethyl cellulose at 50, 100 or 200 mg./ml. and 1 ml. was administered orally per kg. of body weight. Cats were bled periodically after drug administration and serum was collected and assayed for feline interferon on kitten kidney cells using a plaque reduction assay as previously described (Stringfellow and Weed, Am. d. Vet. Res., Vol. 30, page 1963-1967 (1977). As indicated below, in Table 1, the drug effectively induced high levels of serum interferon indicating that it will be an effective antiviral agent in cats.

                  TABLE 1                                                          ______________________________________                                         Serum interferon levels (units/ml.) after oral administration of               2-amino-5-bromo-6-phenyl-4-pyrimidinol                                         Dose             Hours post drug administration                                (mg./kg.)                                                                               Cat #   0        3     6       12                                     ______________________________________                                         200      A        --*     10,200                                                                               1,300   320                                             B       --        5,100                                                                               2,600   1,300                                  100      A       --         640   320   80                                              B       --       20,500                                                                               10,200  ND***                                   50      A       --         640   320   80                                              B       --        1,280                                                                                 80    80                                     Placebo**                                                                               A       --       --    --      --                                              B       --       --    --      --                                     ______________________________________                                          *indicates a liter of less than 50 units/ml.                                   **placebo treated animals received vehicle (1 ml./kg.) without drug.           ***ND = Not done                                                         

Example 37 Effective treatment and prevention of a respiratory tract infection in bovines

Calves were given 2-amino-5-bromo-6-phenyl-4-pyrimidinol (1 gm./calf/day) intranasally once a day for 6 consecutive days beginning either 12 hours before or 6 hours after intranasal infection with infectious bovine rhinotracheitis (IBR) virus. Nasal swabs were collected daily for measurement of virus levels and three weeks after infection all calves were sacrificed and autopsied. The level of pneumonia was determined by gross examination. Using a scoring system of 0 to 5 each lobe of each lung was scored for degree of pneumonia. A score of 0 was given to each lobe with no pneumonia lesions, a score of 5 was complete lobe consolidation. Each lung had 7 lobes giving a maximum total score/lung of 35. The results presented in Table 2 indicate that the drug effectively reduced the severity of infection when given either therapeutically (6 hours after infection) or prophylactically (12 hours before infection). Nasal virus titers corresponded to development of pneumonia.

                  TABLE 2                                                          ______________________________________                                         Treatment      No. calves/group                                                                            Lung lesion score                                  ______________________________________                                         12 hr. before infection                                                                       4            2.0                                                6 hr. after infection                                                                         4            5.0                                                Placebo given beginning                                                                       4            14.0                                               12 hr. before infection                                                        ______________________________________                                    

Example 38

Following the procedure of Examples 36-37 but substituting for 2-amino-5-bromo-6-phenyl-4-pyrimidinol the compositions described in Examples 22 through 35, inclusive, virus infection is prevented or treated and interferon production is induced. 

We claim:
 1. A compound of the formula: ##STR26## wherein X₃ is equal to X, X₄, or X₅ wherein X₄ is chloro, bromo or iodo, and X₅ is mono-, di-or trihalomethyl, mono-, di-or trifluoroethyl, perfluoropropyl, and wherein X is alkyl of from 1 to 3 carbon atoms, inclusive, 2-propynyl and 2-propenyl, and X₁ is a member selected from the group consisting of(a) phenyl, provided that when X₃ is bromo or X, X₁ is not phenyl, (b) a monosubstituted phenyl of the formula: ##STR27## wherein one of the groups, R, R₁, R₂, R₃, R₄ is not hydrogen and wherein R or R₄ is alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms, alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms, fluoro, chloro, bromo, iodo or nitro with the proviso that when R or R₄ is chloro, X₃ is not ethyl; R₁ or R₃ is fluoro, chloro, bromo, iodo, nitro; trifluoromethyl or alkoxy of from 1 to 8 carbon atoms; alkoxyethyloxy wherein alkoxy is from 1 to 3 carbon atoms, inclusive, or ##STR28## wherein R₅ and R₆ are the same or different and are alkyl of from 1 to 8 carbon atoms, inclusive, benzyl, or taken together with --N< are a saturated cycloalkylamino group ##STR29## wherein n' is 3, 4, 5 or 6 or dialkyl substituted cycloalkylamino wherein each alkyl is from 1 to 3 carbon atoms, inclusive, with the proviso that when R₁ or R₃ is iodo, X₃ is not chloro; and R₂ is chloro, fluoro, bromo, iodo, or alkyl of from 1 to 3 carbon atoms, inclusive; (c) a disubstituted phenyl of the formula: ##STR30## wherein any two of R, R₁, R₂, R₃ and R₄ are not hydrogen and are the same or different and are fluoro, chloro, bromo, iodo, alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms thereof, alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms thereof, nitro and trifluoromethyl, with the proviso that R and R₁ or R₃ and R₄ are not both methoxy; (d) a trihalo substituted phenyl wherein hal is chloro, bromo or iodo; (e) α-naphthyl of the formula: ##STR31## wherein R₇ is substituted in either ring and is hydrogen, alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms, alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms, fluoro, chloro, iodo, bromo or nitro; provided that when X₃ is X, X₁ is not α-naphthyl, (f) 2-furyl, (g) 3-pyridyl, (h) 2-pyridyl and (i) 2-pyrazyl, provided when X₃ is X, X₁ is not 2-furyl, 3-pyridyl, 2-pyridyl, or 2-pyrazyl, or a salt thereof.
 2. A compound according to claim 1 wherein X₃ is chloro, bromo, or iodo.
 3. A compound according to claim 1 wherein X₃ is alkyl of from 1 to 3 carbon atoms.
 4. A compound according to claim 1 wherein X₁ is phenyl, excluding 2-amino-5-bromo-6-phenyl-4-pyrimidinol, and X₃ is chloro, bromo or iodo.
 5. A compound according to claim 1 wherein X₁ is a member selected from the group consisting of(a) a monosubstituted phenyl of the formula: ##STR32## wherein one of the groups, R, R₁, R₂, R₃, R₄ is not hydrogen and wherein R or R₄ is alkyl of from 1 to 8 carbon atoms, inclusive alkoxy of from 1 to 8 carbon atoms, inclusive, fluoro, chloro, bromo, iodo or nitro; R₁ or R₃ is fluoro, chloro, bromo, iodo, nitro; trifluoromethyl or alkoxy of from 1 to 8 carbon atoms, alkoxyethyloxy wherein alkoxy is from 1 to 3 carbon atoms, inclusive, or ##STR33## wherein R₅ and R₆ are the same or different and are alkyl of from 1 to 8 carbon atoms, inclusive, benzyl, or taken together with --N< are a saturated cycloalkylamino group ##STR34## wherein n' is 3, 4, 5 or dialkyl substituted cycloalkylamino wherein each alkyl is from 1 to 3 carbon atoms, inclusive, with the proviso that when R₁ or R₃ is iodo, X₃ is not chloro; and R₂ is chloro, fluoro, bromo, iodo, or alkyl of from 1 to 3 carbon atoms, inclusive; (b) a disubstituted phenyl of the formula: ##STR35## wherein any two of R, R₁, R₂, R₃ and R₄ are not hydrogen and are the same or different and are fluoro, chloro, bromo, iodo, alkyl of from 1 to 8 carbon atoms, alkoxy of from 1 to 8 carbon atoms, nitro and trifluoromethyl, with the proviso that R and R₁ or R₃ and R₄ are not both methoxy; (c) a trihalo substituted phenyl wherein hal is chloro, bromo or iodo; (d) α-naphthyl of the formula: ##STR36## wherein R₇ is substituted in either ring and is hydrogen, alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms, alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms, fluoro, chloro, iodo, bromo or nitro; (e) 2-furyl, (f) 3-pyridyl, (g) 2-pyridyl and (h) 2-pyrazyl, and X₃ is chloro, bromo or iodo or a salt thereof.
 6. A compound according to claim 1 which is 2-amino-5-iodo-6-(3-bromophenyl)-4-pyrimidinol.
 7. A compound according to claim 1 which is 2-amino-5-bromo-6-(3-fluorophenyl)-4-pyrimidinol.
 8. A compound according to claim 1 which is 2-amino-5-bromo-6-(2-methoxyphenyl)-4-pyrimidinol.
 9. A compound according to claim 1 which is 2-amino-5-chloro-6-(2-methoxyphenyl)-4-pyrimidinol.
 10. A compound according to claim 1 which is 2-amino-5-iodo-6-(2-methoxyphenyl)-4-pyrimidinol.
 11. A compound according to claim 1 which is 2-amino-5-bromo-6-(3-chlorophenyl)-4-pyrimidinol.
 12. A compound according to claim 1 which is 2-amino-5-iodo-6-(3-chlorophenyl)-4-pyrimidinol.
 13. A compound according to claim 1 which is 2-amino-5-chloro -6-(3-chlorophenyl)-4-pyrimidinol.
 14. A compound according to claim 1 which is 2-amino-5-chloro-6-(2-fluorophenyl)-4-pyrimidinol.
 15. A compound according to claim 1 which 2-amino-5-chloro-6-(3-fluorophenyl)-4-pyrimidinol.
 16. A compound according to claim 1 which is 2-amino-5-bromo-6-(2-fluorophenyl)-4-pyrimidinol .
 17. A compound according to claim 1 which is 2-amino-5-iodo-6-(3-fluorophenyl)-4-pyrimidinol.
 18. A compound according to claim 1 which is 2-amino-5-iodo-6-phenyl -4-pyrimidinol.
 19. A compound according to claim 1 which is 2-amino-5-chloro-6-phenyl -4-pyrimidinol.
 20. A compound according to claim 1 which is 2-amino-5-iodo-6-(2-fluorophenyl)-4-pyrimidinol.
 21. A compound according to claim 1 which is 2-amino-5-chloro-6-(3-methoxyphenyl)-4-pyrimidinol.
 22. A compound according to claim i which is 2-amino-5-bromo-6-(3-methoxyphenyl)-4-pyrimidinol.
 23. A compound according to claim 1 which is 2-amino-5-iodo-6-(3-methoxyphenyl)-4-pyrimidinol.
 24. A compound according to claim 1 which is 2-amino-5-bromo-6-(2-pyridyl)-4-pyrimidinol.
 25. A compound according to claim 1 which is 2-amino-5-iodo-6-(3,4-dichlorophenyl)-4-pyrimidinol.
 26. A compound according to claim 1 which is 2-amino-5-bromo-6-(α-naphthyl)-4-pyrimidinol.
 27. A compound according to claim 1 which is 2-amino-5-chloro-6-(3-nitrophenyl)-4-pyrimidinol.
 28. A compound according to claim 1 which is 2-amino-5iodo-(3-nitrophenyl)-4-pyrimidinol.
 29. A compound according to claim 1 which is 2-amino-5-iodo-6-(3-trifluoromethylphenyl)-4-pyrimidinol.
 30. A compound according to claim 1 which is 2-amino-5-bromo-6-(4-fluorophenyl)-4-pyrimidinol.
 31. A compound according to claim 1 which is 2-amino-5-bromo-6-(3,5-dimethoxyphenyl)-4-pyrimidinol.
 32. A compound according to claim 1 which is 2-amino-5-chloro-6-(3-propyloxyphenyl)-4-pyrimidinol.
 33. A process for preventing or treating vital infections or inducing interferon production comprising the administration of a compound of the formula: ##STR37## wherein X₃ is equal to X, X₄, or X₅ wherein X₄ is chloro, bromo or iodo, and X₅ is mono-, di-or trihalomethyl, mono-, di-or trifluoroethyl, perfluoropropyl, and wherein X is alkyl of from 1 to 3 carbon atoms, inclusive, 2-propynyl and 2-propenyl, and X₁ is a member selected from the group consisting of(a) phenyl, (b) a monosubstituted phenyl of the formula: ##STR38## wherein one of the groups, R, R₁, R₂, R₃, R₄ is not hydrogen and wherein R or R₄ is alkyl of from 1 to 8 carbon atoms, inclusive, alkoxy of from 1 to 8 carbon atoms, inclusive, fluoro, chloro, bromo, iodo or nitro; R₁ or R₃ is fluoro, chloro, bromo, iodo, nitro; trifluoromethyl or alkoxy of from 1 to 8 carbon atoms, alkoxyethyloxy wherein alkoxy is from 1 to 3 carbon atoms, inclusive, or ##STR39## wherein R₅ and R₆ are the same or different and are alkyl of from 1 to 8 carbon atoms, inclusive, benzyl, or taken together with --N< are a saturated cycloalkylamino group ##STR40## wherein n' is 3, 4, 5 or 6 or dialkyl substituted cycloalkylamino wherein each alkyl is from 1 to 3 carbon atoms, inclusive, with the proviso that when R₁ or R₃ is iodo, X₃ is not chloro; and R₂ is chloro, fluoro, bromo, iodo, or alkyl of from 1 to 3 carbon atoms, inclusive; (c) a disubstituted phenyl of the formula: ##STR41## wherein any two of R, R₁, R₂, R₃ and R₄ are not hydrogen and are the same or different and are fluoro, chloro, bromo, iodo, alkyl of from 1 to 8 carbon atoms, alkoxy of from 1 to 8 carbon atoms, nitro and trifluoromethyl, with the proviso that R and R₁ or R₃ and R₄ are not both methoxy; (d) a trihalo substituted phenyl wherein hal is chloro, bromo or iodo; (e) α-naphthyl of the formula: ##STR42## wherein R₇ is substituted in either ring and is hydrogen, alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms, alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms, fluoro, chloro, iodo, bromo or nitro; (f) 2-furyl, (g) 3-pyridyl, (h) 2-pyridyl and (i) 2-pyrazyl, or a salt thereof in association with a pharmaceutical carrier to a human or animal.
 34. A process of claim 33 wherein the compound is 2-amino-5-bromo-6-phenyl -4-pyrimidinol.
 35. A process of claim 33 wherein the compound is selected from the group consisting of2-amino-5-iodo-6-(3-bromophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(2-fluorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-fluorophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-phenyl-4-pyrimidinol, 2-amino-5-iodo-6-phenyl-4-pyrimidinol, 2-amino-5-chloro-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-pyridyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3,4-dichlorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(α-naphthyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-nitrophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-nitrophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-trifluoromethylphenyl)-4-pyrimidinol, 2-amino-5-ethyl-6-phenyl-4-pyrimidinol, 2-amino-5-bromo-6-(3,5-dimethoxyphenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-propyloxyphenyl)-4-pyrimidinol.
 36. A process for preventing or treating viral infections comprising the administration of 2-amino-5-bromo-6-phenyl-pyrimidinol or a salt thereof in association with a pharmaceutical carrier to a human.
 37. A process of claim 36 wherein the human is infected or likely to be infected with a hepatitis virus.
 38. A process of claim 36 wherein the human is infected or likely to be infected with a papovavirus.
 39. A process for inducing interferon production comprising the administration of 2-amino-5-bromo-6-phenyl-pyrimidinol or a salt thereof in association with a pharmaceutical carrier to a human.
 40. A process of claim 36 wherein the human is infected or likely to be infected with a herpes virus.
 41. A medicinal composition comprising, in a unit dosage form selected from the group consisting of a tablet, capsule, pill, suppository, sterile parenteral solution or sterile parenteral suspension, sterile non-parenteral solution, sterile non-parenteral suspension, sweetened oral solution and sweetened oral suspension, a compound selected from the group consisting of compounds of the formula: ##STR43## wherein X₃ is equal to X, X₄, or X₅ wherein X₄ is chloro, bromo or iodo, and X₅ is mono-, di- or trihalomethyl, mono-, di-or trifluoroethyl, perfluoropropyl, and wherein X is alkyl of from 1 to 3 carbon atoms, inclusive, 2-propynyl and 2-propenyl, and X₁ is a member selected from the group consisting of(a) phenyl, (b) a monosubstituted phenyl of the formula: ##STR44## wherein one of the groups, R, R₁, R₂, R₃, R₄ is not hydrogen and wherein R or R₄ is alkyl of from 1 to 8 carbon atoms, inclusive, alkoxy of from 1 to 8 carbon atoms. fluoro, chloro, bromo, iodo or nitro; R₁ or R₃ is fluoro, chloro, bromo, iodo, nitro; trifluoromethyl or alkoxy of from 1 to 8 carbon atoms, alkoxyethyloxy wherein alkoxy is from 1 to 3 carbon atoms, inclusive, or ##STR45## wherein R₅ and R₆ are the same or different and are alkyl of from 1 to 8 carbon atoms, inclusive, benzyl, or taken together with --N< are a saturated cycloalkylamino group ##STR46## wherein n' is 3, 4, 5 or 6 or dialkyl substituted cycloalkylamino wherein each alkyl is from 1 to 3 carbon atoms, inclusive, with the proviso that when R₁ or R₃ is iodo, X₃ is not chloro; and R₂ is chloro, fluoro, bromo, iodo, or alkyl of from 1 to 3 carbon atoms, inclusive; (c) a disubstituted phenyl of the formula: ##STR47## wherein any two of R, R₁, R₂, R₃ and R₄ are not hydrogen and are the same or different and are fluoro, chloro, bromo, iodo, alkyl of from 1 to 8 carbon atoms, alkoxy of from 1 to 8 carbon atoms, nitro and trifluoromethyl, with the proviso that R and R₁ or R₃ and R₄ are not both methoxy; (d) a trihalo substituted phenyl wherein hal is chloro, bromo or iodo; (e) α-naphthyl of the formula: ##STR48## wherein R₇ is substituted in either ring and is hydrogen, alkyl of from 1 to 8 carbon atoms, inclusive, including isomeric forms, alkoxy of from 1 to 8 carbon atoms, inclusive, including isomeric forms, fluoro, chloro, iodo, bromo or nitro; (f) 2-furyl, (g) 3-pyridyl, (h) 2-pyridyl and (i) 2-pyrazyl,provided when X₃ is X, X₁ is not 2-furyl, 3-pyridyl, 2-pyridyl or 2-pyrazyl; or a salt thereof in association with a pharmaceutical carrier.
 42. The composition of claim 41 wherein the compound selected is 2-amino-5-chloro-6-(3-methoxyphenyl)-4-pyrimidinol.
 43. A composition according to claim 41 wherein the compound is selected from the group consisting of2-amino-5-iodo-6-(3-bromophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(2-fluorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-fluorophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-phenyl -4-pyrimidinol, 2-amino-5-iodo-6-phenyl-4-pyrimidinol, 2-amino-5-chloro-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-pyridyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3,4-dichlorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(α-naphthyl)-4-pyrmidinol, 2-amino-5-chloro-6-(3-nitrophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-nitrophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-trifluoromethylphenyl)-4-pyrimidinol, 2-amino-5-ethyl-6-phenyl -4-pyrimidinol, 2-amino-5-bromo-6-(3,5-dimethoxyphenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-propyloxyphenyl)-4-pyrimidinol.
 44. A pharmaceutical composition comprising, in tablet or capsule form, from about 50 to about 500 milligrams of a compound selected from the group consisting of2-amino-5-iodo-6-(3-bromophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(2-fluorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-fluorophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-phenyl-4-pyrimidinol, 2-amino-5-bromo-6-phenyl -4-pyrimidinol, 2-amino-5-iodo-6-phenyl-4-pyrimidinol, 2-amino-5-chloro-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino -5-bromo-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-pyridyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3,4-dichlorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(α-naphthyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-nitrophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-nitrophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-trifluoromethylphenyl)-4-pyrimidinol, 2-amino-5-ethyl-6-phenyl-4-pyrimidinol, 2-amino-5-bromo-6-(3,5-dimethoxyphenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-propyloxyphenyl)-4-pyrimidinol,or a pharmaceutically acceptable acid addition salt, alkali metal or alkaline earth metal salt thereof, in association with a pharmaceutical carrier.
 45. A sterile pharmaceutical composition for parenteral administration comprising from about 0.5 to about 50 percent, w/v, of a compound selected from the group consisting of2-amino-5-iodo-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(2-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-chlorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(2-fluorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-fluorophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-fluorophenyl)-4-pyrimidinol, 2-amino-5-chloro-6-phenyl-4-pyrimidinol, 2-amino-5-bromo-6-phenyl -4-pyrimidinol, 2-amino-5-iodo-6-phenyl-4-pyrimidinol, 2-amino-5-chloro-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-methoxyphenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(2-pyridyl)-4-pyrimidinol, , 2-amino-5-iodo-6-(3,4-dichlorophenyl)-4-pyrimidinol, 2-amino-5-bromo-6-(α-naphthyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-nitrophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-nitrophenyl)-4-pyrimidinol, 2-amino-5-iodo-6-(3-trifluoromethylphenyl)-4-pyrimidinol, 2-amino-5-ethyl-6-phenyl-4-pyrimidinol, 2-amino-5-bromo-6-(3,5-dimethoxyphenyl)-4-pyrimidinol, 2-amino-5-chloro-6-(3-propyloxyphenyl)-4-pyrimidinol,or pharmaceutically acceptable acid addition salt, alkali metal or alkaline earth metal salt thereof, in association with a sterile pharmaceutical carrier.
 46. A medicinal composition comprising, in a unit dosage form selected from the group consisting of a tablet, capsule, pill, suppository, sterile parenteral solution or sterile parenteral suspension, sterile non-parenteral solution, sterile non-parenteral suspension, sweetened oral solution and sweetened oral suspension, 2-amino-5-bromo-6-phenyl-4-pyrimidinol in association with a pharmaceutical carrier.
 47. A medicinal composition comprising, in a unit dosage form selected from the group consisting of a tablet, capsule, pill, suppository, sterile parenteral solution or sterile parenteral suspension, sterile non-parenteral solution, sterile non-parenteral suspension, sweetened oral solution and sweetened oral suspension, 2-amino-5-bromo-6-phenyl-4-pyrimidinol or a salt thereof in association with a pharmaceutical carrier.
 48. A pharmaceutical composition comprising, in tablet or capsule form, from about 50 to about 500 milligrams of 2-amino-5-bromo-6-phenyl-4-pyrimidinol in association with a pharmaceutical carrier.
 49. A sterile pharmaceutical composition for parenteral administration comprising from about 0.5 to about 50 percent, w/v, of 2-amino-5-bromo-6-phenyl-4-pyrimidinol in association with a sterile pharmaceutical carrier. 